My understanidng is that valet parking is free (for DVC members) at the BWV and VWL. It doesn't matter if you are staying at a DVC resort, a WDW hotel, off site or just visiting for the day. OF course, a tip is still appropriate. Others have posted that valet parking will be free for DVC members at the BC/YC/BCV when the BCV open in July.
Valet parking is NOT free anywhere else, but you only have to pay the fee once per day. So if you are asking about valet parking at the CR, valet parking is NOT free there, even if you are staying on points.
Valet parking is free at all the deluxe resorts if you have a valid handicapped parking permit.