I found following festivals to submit your work. Add some more please!
Future of story telling FoST FEST. October 7-9, New York City, USA
Kaleidoscope tour. ???
Vr Fest. January 6-9, Las Vegas, USA
LICHTER Filmfest March 29 – 03 April , Frankfurt, DE
And this is a first entry for VR cinema in my list:
The Virtual Cinema Amsterdam, Netherlands EU. Oosterdokskade 5
HMD related and other platforms:
Full Dome Festivals:
full dome festival, Jena, DE EU
If you have additions or corrections, let me know.