I don't know that I have found any 'full on' WAM VR... yet! Though tagging this thread to keep an eye out! There are some porn scenes with a little bit of oil if you look around. A few others with girls playing in the ocean or a pool.
The question has come up on here before. It seems like the general consensus was that (good) VR is definitely harder to shoot/edit/produce. Also, VR is a small percentage of all porn and WAM is a small percentage of all porn, so VR WAM is an exceedingly small percentage of all porn. On the plus side, the technology is getting better every day, so easier/faster/cheaper to shoot and produce VR.
Conversely, I would not underestimate the novelty of watching 'normal' 2D WAM scenes in a VR headset. (especially if they happen to be POV) There is certainly some fun in being able to block out the whole rest of the world, focus totally on the scene no matter where you look and have both hands free - lol
For added effect you can even play around in the substance from the video while watching. Just be careful - I lost some earphones playing along to Jayce's molasses scene and still trying to get mud out of the focus mechanism on my headset due to another scene!
Maybe some day we can combine VR headset with a diving mask.... and snorkel !