Like others said, there's no NCAA ban on selling alcohol at on-campus facilities, but there are very, very few that still do...I know that a couple of years ago Tulsa, UH, and a couple of California schools (San Jose State?) still did, but most don't, outside of the 'club' thing.
Most schools who play in a pro stadium don't have control over the concessions, so that's why you'll get beer in places like Tulane, or at the Rose Bowl. The NCAA tournament makes it a condition of getting awarded a site that you won't sell during a game, so the year we won the regional in San Antonio, you couldn't get beer during the game even though it flows like water during the Alamo Bowl. I'm not sure what the deal is with the club level at Reliant for the NCAA tourney, hopefully I'll find out in a couple of weeks...