Going to be pretty crap either way in most cases. That said working in a pub/food/drink service environment might give you some more relevant experience for applying to other roles in future (whereas working in a high street retail store doesn't add anything beyond what the pub work already gives you). Also debatably for a pub, if it's a privately owned one and not part of a chain you might have the odd chance of having a decent management, whereas any high street retailer is invariably going to have the same issues with management regardless of how nice the person is (due to the unrealistic performance expected from managers and their stores anyway).