Definitely not usual for a crew to behave like that. My wife and I ran our boat as a crewed charter a few years back, also on a half board basis with most lunches aboard at anchor or moored, and evening meals were ashore at a restaurant. We would never have invited ourselves out with the guests without being asked. And, if asked, we would certainly not have drunk one bottle of wine, never mind two! They are not only inconsiderate but endangering the guests by consuming that much alcohol while in charge of the boat and your safety.