Auburn was ranked 7 and lost to a 21 ranked Wisconsin team. You can make the argument that they beat this and that team and held together with another team, but it comes down to wins and losses. If you win the games you're suppose to, then you'll be in good shape to have a good rank. Unfortunately, Auburn had two losses to teams that they should have beat (Wisconsin and Georgia Tech). By the way Auburn is ranked 14 followed by Wisconsin at 15, despite the bowl game victory.
On a side note, I think the SEC is one of the MOST respected conferences in the US for football. The Big East, on the other hand, is considered full of a bunch of weak teams who some think should not be eligible for a BCS bid as compared to the ACC, SEC, etc.