Every BCS team is pretty much going to play at least 5 teams in conference that get bowl eligible, this year's Big East is an exception because the league was so bad OOC.
Here is how Vanderbilt got eligible:
Elon
Mississippi
Army
Kentucky
UConn
Wake
Western Michigan:
Nichols
CMU
UConn
Bowling Green
Miami
Akron
Ball State
Iowa State had a couple of big wins but still wouldn't have been bowl eligible without a 1 pt win over Northern Iowa.
The Big East is so bad the schedule actually ended up being easier than expected.