The features page doesn't mention it nor explicitly say music files aren't supported. One 3rd party website said only video files will play.
And that's my experience as well. I find it odd that I can transfer music files with iTunes and yet on the iPhone they don't show up.
Forget WiFi transfer; when I launch VLC it only wants me to connect to iTunes (which it already is ...) to transfer videos.
And yet I see hints on this forum people are using it to play music. How?
iPhone 6, iOS 9.x, latest iTunes etc. on El Cap