@Julienstanford - Since my last test, I've upgraded to iOS 10.0.2, and I'm now using the Flow fine from my iPhone.
It could have been a user error incident, as admittedly, I don't use the Flow often, but I connected it again, and I'm currently playing tracks from my iPhone with it.
It could have been a user error incident, as admittedly, I don't use the Flow often, but I connected it again, and I'm currently playing tracks from my iPhone with it.