I like this in the pros, but in a college locker room this could potentially divide a team--especially when the starting position is yet to be won.
Say hypothetically (and I know nothing about any of our QB's families) that qb-B takes the linemen out to dinner. But what if qb-A comes from a poor family and doesn't have the personal resources to spend that way?
The previously irrelevant factor of who has money and who doesn't has now entered the locker room in a real--not symbolic--way. It would be natural human behavior for the guys coming from poor families to begin to identify with each other. Not good.
If the QB paying the check is clearly established and accepted by his teammates as the starter, then no problem. But in this situation, it would be better if all the QBs took all the O-linemen out to dinner, and it was left confidential between the QBs who picked up half, most, or all of the check.
No perceived off-field advantage = no division.