I have mentioned this before that if delayed by more than 2 hours I know that BA does refund BoB purchases. Not that it has a choice in the matter. Just keep it reasonable, photo the receipt and items, and perhaps pay with Avios so that repayment can be swift. There probably isn't the stock to give everyone the same item, but if there is a mix of requests for tea, coffee, chocolate etc. then I would hope that most people would get something. There is nothing in EC261 which stops you from claiming alcohol.

And yes if the delay was while sitting in a lounge then that would probably be deemed to meet EC261.