I just noticed I do not earn points on charges to my hotel bill for parking my SUV at the NYC Marriott Marquis overnight. The charge is $60 for cars, and $70 for SUV's. This seems odd to me, as they gave me points on the $6 Starbucks coffee charged to my room. I know they are renovating the parking garage at the Marquis so all cars are parked off site at a 3rd party vendor and wonder if this has something to do with it.
Once or twice I've earned points for parking, but is not the norm. I understand it when parking is in a nearby structure not owned by the hotel. I do think that if the packing facility is owned and operated by the hotel, parking charges should earn points. I suppose it's possible that this latter scenario doesn't happen as often as we think.
If you are spending at the hotel and it gets added to your final hotel bill that should be points earned. I traveled to DC a lot in 2010 - 2012, I was earning $20+ to points per day and I was there practically a year with a week or so for home trip. So maybe it is depending on the property, but again what you spend at the hotel is my thoughts!