Exactly that, Rebecca.
I used to manage a bar, pre babies, one not unlike BrewDog in customer base. Good bar staff develop relationships with the customers, and when customers tip, it’s because they want the staff to have the money.
Nothing wrong with also having a charity collection box on the bar, but expecting all staff to hand over all tips for a month, to a charity they may or may not personally wish to support? That’s utterly wank behaviour.
Most bar staff are on minimum wage or not much more, working antisocial hours (and some subsequently have to shell out for taxis to get home safely). Let the fucking company donate, but leave the staff’s tips alone.