I am having the same issue. In the past (iOS6) I have tried disabling then re-enabling iTunes Match with mixed results, but I am reluctant to do that because sometimes turning it off and on again deletes all of the locally stored music on my iPhone. What does seem to fix it is:
. Turn off iTunes Match in the device
. Connect to a computer
. Sync music / playlists from computer
. Unplug from computer
. Turn iTunes Match back on in the device
Wouldn't it be nicer if we could just drag down on the playlist screen to get iTunes Match to refresh the playlists (like checking for new mail in the Mail app)?