Ever since I got Match, none of my plays on my iPhone 4S sync back to alter the playcounts on the Mac, as they always used to (before Match). It has been driving me crazy and I've found out how to correct it..
Turn off Match. I've just verified that playcounts do now increase on Mac when they are played on the iPhone following a sync.
This also sorts the issue of artwork not syncing from Mac to iPhone (lots of other people, myself included, have been having this problem).
Bit of a pain to turn off Match, seeing as I paid for it, but it does then sync all the music into the iPhone and thus eliminate the problem of large data usage when you play music when you are out of wi-fi. Every cloud and all that..