It would vary. If redeeming points the guests should all get platinum or whatever status you had. This includes any benefits like lounge access, welcome gift, etc.

When paying for a room, it basically needs your name on the reservation. I asked a similar question before in the forum here and one thing you can try is add your name on the reservation also so there's two names. Call up the reservation to have this added. That other person can check in and tell the front desk you are coming in late if they ask questions. I haven't tried this myself but was told by others it worked for them.