[PrinceLightfoot]

So where would the game be in 2015 if neither Pac-12 champ nor Big 10 champ make the four-team playoff?

For this year if considered worthy by the committee, they would be sent to either the Cotton, Fiesta, or the Peach. They would not necessarily play each other, though. Note that a mid major team is guaranteed at least one spot in the bowls below from the "Group of Five" (The American, Conference USA, MAC, Mountain West and Sun Belt).

2014 season
Rose Bowl - two of the top four teams (playoff location)
Sugar Bowl - two of the top four teams (playoff location)
Cotton Bowl - at large selections or "Group of Five"
Fiesta Bowl - at large selections or "Group of Five"
Orange Bowl - ACC #1 vs SEC #2, Big Ten #2, or ND
Peach Bowl - at large selections or "Group of Five"

[PrinceLightfoot]

So where would the game be in 2015 if neither Pac-12 champ nor Big 10 champ make the four-team playoff?

For this year if considered worthy by the committee, they would be sent to either the Cotton, Fiesta, or the Peach. They would not necessarily play each other, though. Note that a mid major team is guaranteed at least one spot in the bowls below from the "Group of Five" (The American, Conference USA, MAC, Mountain West and Sun Belt).

2014 season
Rose Bowl - two of the top four teams (playoff location)
Sugar Bowl - two of the top four teams (playoff location)
Cotton Bowl - at large selections or "Group of Five"
Fiesta Bowl - at large selections or "Group of Five"
Orange Bowl - ACC #1 vs SEC #2, Big Ten #2, or ND
Peach Bowl - at large selections or "Group of Five"