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If oklahoma makes the playoffs over OSU, that could bump PSU out of a NY6 bowl.

If Oklahoma makes the playoffs, then Big 12 gets to send another team to the Sugar Bowl, probably Texas.  That would be enough to bump PSU down.

If you are correct, and I'll assume that you are, then it seems to me that PSU is probably screwed either way:

• If Texas wins:  Texas automatically gets a NY6 bowl as a P5 Champion and Oklahoma at 11-2 would still beat out PSU at 9-3.  
• If Oklahoma wins:  Oklahoma most likely gets the last CFP berth and, per your explanation, Texas gets to be their replacement in the Sugar Bowl.  

So if this is correct then I can only see two ways for PSU to get a NY6 bowl:

• Georgia and Oklahoma both win, the CFP takes 12-1 Bama over 12-1 Oklahoma.  Oklahoma goes to the Sugar Bowl and PSU obviously finishes ahead of Texas.  
• Oklahoma and Ohio State both win and the CFP takes 12-1 tOSU over 12-1 Oklahoma.  Oklahoma goes to the Sugar Bowl and PSU obviously finishes ahead of Texas.  

https://collegefootballnews.com/2018/01/college-football-bowl-ties-affiliations-tie-ins-college-football-playoff-conference-2018-2019

That was helpful, thank you.  It confirms what @LittlePig said.  Per CFN, the Rose will be B1G/PAC and the Sugar will be B12/SEC no matter what.  
WRT the PAC this is all pretty irrelevant because the the P12CG winner goes to the Rose and the P12CG loser does not get a NY6 bowl and that is that.  
WRT the SEC this is all pretty irrelevant because the SEC will have plenty of credible at-large teams even if they get two in the CFP.  
WRT the B1G this is all pretty irrelevant because the B1G will have plenty of credible at-large teams even if the Buckeyes make the CFP.  
That leaves the B12:
Current rankings of B12 teams:

• #5, 11-1 Oklahoma
• #14, 9-3 Texas
• #16, 8-3 WVU
• #23, 7-4 ISU

With a B12CG win over #5 OU, the Longhorns would obviously jump #12 Penn State but that is completely irrelevant because with the win the Longhorns would get an auto-bid as B12 Champions.  Penn State's problem is that they have no chance of passing Oklahoma even if the Sooners lose the B12CG.  

Nationally, Northwestern and Pitt are the major potential bid thieves.  Either of them winning would be problematic for "bubble" teams  Florida, LSU, and Penn State.  

Assuming that all of the favorites win (Bama>UGA, Clemson>Pitt, OU>TX, tOSU>NU, UCF>whatever cream-puff they are playing, UW>Utah), I'm pretty sure that the CFP/NY6 Bowls would be as follows:

• CFP Semi-Final #1 Orange:  #1 Bama vs #4 Oklahoma
• CFP Semi-Final #2 Cotton:  #2 Clemson vs #3 Notre Dame
• Rose:  Ohio State vs Washington
• Sugar:  Texas vs Georgia
• Peach:  Michigan vs LSU?^
• Fiesta:  UCF vs Florida?^

^Note that in this scenario the last four teams are LSU, Florida, UCF, and Michigan.  They obviously are not going to have two SEC teams that already played each other play in a bowl so Michigan would get either LSU or Florida with the other SEC team getting UCF.  Also, UCF played in the Peach Bowl last year so if they go again this year, it would have to be to the Fiesta (at least as I understand all of this).  

To borrow basketball lingo, Penn State would be the "next team out", but it isn't easy to concoct a scenario that gets them in.  Texas is the "bid thief" that keeps PSU out but the only way to exclude the Longhorns (see above) is for OU to win the B12 but miss the playoff.  I can only possibly see that if:

• Bama loses to UGA and gets a CFP bid anyway, or
• Ohio State just blows the doors off of Northwestern and passes OU for the #4 spot in the CFP.  

The last teams in, in order, in this scenario are:

• LSU
• Florida
• Michigan

Thus, any additional bid-thieves would cost those teams NY6 bowl bids.  Ie:

• If Northwestern beats Ohio State the Wildcats would get an auto-bid but the 11-2 Buckeyes would still be ahead of 10-2 Michigan, 9-3 Florida, and 9-3 LSU so one of them (probably LSU) would get knocked out.  
• If Pitt beats Clemson the Panthers would get an auto-bid but the 12-1 Tigers would still be ahead of M/UF/LSU so one of them (probably LSU) would get knocked out.  

If Northwestern and Pitt both win then LSU and Florida would probably both be knocked out.  In that scenario (assuming the rest of the favorites all win):

• CFP Semi-Final #1, Orange:  #1 Bama vs #4 Oklahoma
• CFP Semi-Final #2, Cotton:  #2 Notre Dame vs #3 Clemson
• Rose:  Northwestern vs Washington
• Sugar:  Texas vs Georgia
• Peach:  Pitt vs Ohio State^
• Fiesta:  UCF vs Michigan^

^Note that in this scenario the last four teams are tOSU, M, UCF, and Pitt.  They obviously are not going to have two B1G teams that already played each other play in a bowl so Pitt would get either tOSU or Michigan with the other B1G team getting UCF.  Also, UCF played in the Peach Bowl last year so if they go again this year, it would have to be to the Fiesta (at least as I understand all of this).  

In the event that Bama loses but gets into the CFP ahead of Oklahoma and Ohio State anyway and PSU gets a NY6 berth, here is what I would assume (assuming all other favorites win):

• CFP Semi-Final #1, Orange:  #1 Clemson vs #4 Bama
• CFP Semi-Final #2, Cotton:  #2 Notre Dame vs #3 Georgia
• Rose:  Ohio State vs Washington
• Sugar:  Oklahoma vs Florida
• Peach:  LSU vs PSU^
• Fiesta:  UCF vs Michigan^

^Note that in this scenario the last four teams are PSU, M, UCF, and LSU.  They obviously are not going to have two B1G teams that already played each other play in a bowl so LSU would get either PSU or M with the other B1G team getting UCF.  Also, UCF played in the Peach Bowl last year so if they go again this year, it would have to be to the Fiesta (at least as I understand all of this).  

UCF will go to the Fiesta if they beat Memphis. Big if with Milton out. Won by just one (31-30) in the regular season with him. Orange Bowl is CFP semifinal so no PSU.

FWIW: the ranked G5 teams and who they are playing this weekend:

• #6 UCF vs nr 8-4 Memphis
• #22 Boise State vs #25 Fresno State

Even if Memphis wins they aren't going to jump the Boise/Fresno winner so the G5 team in the NY6 Bowls will be one of those three.  It matters which for placement because they will avoid sending UCF to the Peach Bowl if possible since they went last year.  With Boise or Fresno they would have no such limitation but it might not matter because it would obviously be preferable to send either of those teams to Arizona for the Fiesta Bowl rather than all the way across the country to Georgia for the Peach Bowl.  Thus, the G5 rep is pretty much a lock for the Fiesta.  

What would be some interesting bowl matchups you'd like to watch independent of whether they are likely?

Penn State - LSU?  Michigan - Florida?  Switch pairings?  Washington - Ohio State?  Eh.  Syracuse - PSU?  Mebbe.

OU - Ohio State would be entertaining, and probably record setting.

UCF - Michigan would have been interesting had the QB stayed healthy.

UCF will go to the Fiesta if they beat Memphis. Big if with Milton out. Won by just one (31-30) in the regular season with him. Orange Bowl is CFP semifinal so no PSU.

Ah, OK. I didn't realize the OB was a semi.

So, the Sugar is obligated to take a XII team, even if they aren't in the Top-12?

I read that CFN link that was posted earlier and at least according to that, yes.  Same goes for an SEC team in the Sugar and the B1G and PAC teams in the Rose.  
It doesn't matter with the other conferences because:

• PAC isn't getting into the CFP so their Champion will be in the Rose.  
• B1G will have an available team in the top-12 (Michigan) even if tOSU goes to the CFP.  
• SEC will have an available team in the top-12 (Florida) even if both Bama and UGA go to the CFP.  

It matters in the B12 because if OU makes the CFP cut, the next highest ranked B12 team will be either Texas (after losing the B12CG) or WVU and both would be outside of the top-12.