Oops. I don't think I tip the guy who takes them from the car.
Also, last time at Beach Club, a bell took our bags from our room to the loading area. Then our van came and a different guy put our bags on, then stood around looking for a tip. I was already on the van and had tipped the guy in the room - assuming he would put them on the van. Instead, he just dropped them on the pavement and left. I didn't realize I had to tip both guys and I just sat on the van unsure of what to do. So we drove away and the second guy never got his tip.
Personally, I think tipping once each way is enough.