I don't think tips are really expected, but are welcome.
We were frequent RPR club guests, and we treated our stays like cruises: we tipped at the end. We stayed a week once and gave the staff of 8 $150 to have a pizza party on us.
Another time we didn't use the facilities much and just sent them personalized m&m's to thank them after our visit. They cracked up at that. I got a lovely note from one of the managers, and she said she showed them off to the GM.
If we were going around Christmastime, I would send them a package of Hershey's, that always included hot cocoa and beverage stuff and/or limited edition items. They loved that too. I think they can get tired of the same old beverages in the lounge.
If you find it awkward to tip for drinks as you go (they never had out a tip jar for drinks at RPR when we were there), I don't think they'd miss the few bucks. However, please make sure you write to the GM or the hotel directly highlighting what they did for you, and include their names. That is worth its weight in gold, and they will remember you if you return. Or, buy a little gift they can share that you can give them at the end of your visit.
I lost track of how many times we stayed RPR Club, but everyone ALWAYS knew we were coming, and we always had "our" room, without ever asking. We'd check in at the front desk in the lobby, go up to the lounge, greet everyone and they'd tell us our room was ready. We never had to ask for the room number. Now, sadly, all the staff we knew are gone. I miss my Christmas cards from the club staff!