Yes, it is.
As Vahana VR produces video with the h264 standard and with equirectangular projection, it will be compatible with any VR player.
To improve the compatibility and have the best image quality for the Samsung Gear VR, this is the parameter you should set within Vahana VR:
- Output resolution: 4096x2048
- Framerate between 24 and 60 fps
- Profile baseline
- Max GOP: 90
- Bitrate at 5400 kbps
- Audio with AAC-LC, 48 khz, 2 channels, 160 kbps