After the Swindon away game, we got asked to shut up, we had 10 people around a table. When we all shushed for a few minutes, the students in the louder than we were, but the staff didn't care...
It's obvious that they don't like football fans in there. As a chain you'd think they would all operate the same? Maybe it's worth an email to them?
There are laws against discriminating against people on grounds of the way they dress (football shirts) but I can imagine it'll all be 'up to the managers discretion'
I would just not go in there personally.