Having one or two people in a meeting seems fine generally, but I wouldn't push it by having lots of people since the club isn't supposed to be open to non-guests and those without access. I've seen some horrible cases of people abusing the lounges and then snacks and drinks get removed or the lounges become empty spaces when they aren't manned during limited hours. There was also a strange situation where there was someone holding what looked like a team offsite at a lounge in NYC before and the hotel staff came to escort them out of the lounge - very embarrassing for those guests.