VOOM prices have gotten out of control. Pre-pandemic you could get the Surf & Stream for 4 devices for $22 a day. Now the "on sale" price is $43+ a day, and if not on sale, $70+ per day.
The vouchers are "use or lose" each day. I usually take both cards down to my favorite bar at the end of the evening and find out how many vouchers are left on each card, then grab a couple of beers and/or waters to take back to the room.
We always tip a dollar per drink for the D, D+, or Pin voucher. I don't know how Royal compensates the bartenders, and I don't care. I just feel it is the right thing to do for us.
I think you have a limit of 2 bottles of wine per stateroom, but I've never been charged corkage in the MDR. I always ask in advance. If they do charge, I would just bring down a couple of glasses from my stateroom with me.