I don't know if suspensions are really in order in this case. I don't think you can equate being in the bar underage with what Brandt did.
It appears the boys weren't drinking, and that's a distinction that I believe is important. Yes, they weren't supposed to be in the bar but not drinking was a pretty smart move on their part. As for me, being in the bar underage but not drinking is pretty much akin to speeding or some other minor offense.
Run them until they puke? That seems reasonable to me...