I am looking for guidance as to music settings in iTunes for my iPhone. I have subscribed to Match and have all my music on iCloud. I have set my iPhone to access Match and am getting the error that I am not currently subscribed and to use iTunes to subscribe. I already am subscribed. How do I get the system to allow me to access my music using match?
Now we need to go back to what account ID are you signed into the mobile iTunes store with on your iPhone. Because this is the root of the problem you are having.
First go to iTunes on your computer, pull down the Store menu and select "sign out." This will turn off iTunes Match and sign you out of the iTunes store. Now, pull down Store > Sign In. Enter your iTunes Store account ID. After that pull down Store > Turn On iTunes Match. It will take a few minutes to reenable so let it do it's thing.
Next on your iPhone go to Settings > Store. Scroll down to Apple ID, tap it, and tap Sign Out. Next tap Sign In and enter exactly the same account ID you used to sign into the iTunes Store on your computer.