How to reset iCloud status of a song when using apple music
Try the menu item File > Library > Update iCloud Music Library.



I had quit iTunes after initially enabling iCloud Music Library in preferences when it was only partially done uploading.  To get it going again I used this menu item Update iCloud Music Library, the progress indicator in the upper right appeared and it continued uploading.  This was on OS X 10.10.4 and iTunes 12.2.0.145.