If you want to stream your own music library you need to use iTunes to seed your library into iTunes Match. Beyond that you can listen to everything on your phone through streaming without using iTunes at all.
In fact, when you enable iTunes Match on your phone, iTunes synchronization is turned off (which actually can really suck as well since downloading vs streaming music on the phone is very fussy).
You’d think after all these years it wouldn’t continue to be such a shit show, but here we are. Embrace the suck.