You only can use the playlist with the music stored on your phone, but you can listen to your streaming services like Spotify etc. but you can not control in the APP, you have to control in your streaming service app.
Apple Music:
Apple Music is also a Streaming portal, that means even if you download the music, the music is not phisically on your phone, thats why you can not control the music with the remote control or with the Cratoni APP. You only can control music when you sync music from a PC via iTunes.
We are working on it to integrate the control of streaming portals.
That means in your case, that you can listen to your music but you only can control the music with your Apple Music App on your iPhone.