Q: I can't get iCloud to sync my music to my iPhone without plugging it in

You don't "sync" iPhones with iCloud, at all, for anything.  You can stream and download individual songs from iCloud.  If you want to sync music, you use iTunes on your computer.

You need to subscribe to iTunes Match for that.

http://support.apple.com/kb/PH2588

video: http://support.apple.com/kb/VI294

Subscribe: http://support.apple.com/kb/HT4914