We fly short haul from UK. One room for flight deck and cabin crew. Separate briefings, although the flight deck and cabin crew do converse before going out. Occasionally no info available from company, so flight deck will then give cabin crew relevant info.
Company allows for separate buses to allow cabin crew to go out first, but usually flight deck come in early and so are ready same time as cabin crew, thus almost always use just one bus. Same for going back to crew room - usually flight deck wait for cabin crew and use one bus.