In-Hotel instant rewards is where they allow you to redeem points towards things like the spa... Sometimes you can have them convert charges at checkout to points.
On another note, I had a reservation that was past the cancellation point that was booked on cash and the hotel is on this list. I called up SPG Plat line and they had it switched over to a points reservation. They called the hotel to waive the cancellation fee on the first one since it is being rebooked right away.
