It seems the only people receiving bans were those ejected by stewards at the Ajax, and not rounded up by Barber's fun police. It does not seem unreasonable that the club will then issue a ban.
It's a real shame, as I enjoyed having a pint at my seat before the game. Given that I had well over an hour to kill before kickoff it was a civilised way to pass the time. I understand the celebratory urge to luzz, but it is just selfish behaviour, pour the beer over your own head if you must.