Club vibe is always available, but you might have to activate it when you start a gathering, particularly if your active Sim is not the leader. It's a bit clunky to do, but click on the leader and find the club section in his social context menu, then just cycle to set club vibe and pick the one you want. You can unlock multiple vibes if you want to, for situational utility. The default happy buff is also generally useful and can be upgraded to higher levels. Rally the troops works the same way. Definitely hit Rally the troops every-so-often, as it will help refill your need bars. I'm not sure if there is a cool down on it, but I've used it multiple times on the same gathering. Extremely useful unlock.