How Apple Music and iTunes Match work together?
Apple Music and iTunes Match are complementary:


both will allow you to match (and upload if unmatched) your locally owned songs
Apple Music allows you to stream those songs as well as a good deal (but not the whole) of the iTunes Store catalog without downloading them, or download the matched songs as 256kbps FairPlay-wrapped DRM-encrypted AAC as well as the unmatched ones in their original format.
iTunes Match allows you to download (and listen as it downloads, even if it is in a temporary cache, which makes it look like streaming) matched songs as DRM-free 256kbps AAC (still wrapped in an thin FairPlay container but inconsequential and unencrypted) as well as the unmatched ones in their original format.


So be very wary with Apple Music matched songs: be sure to back up your original files, or you'll be left with only DRMized ones. You can see the type of match by adding some info columns in the song list view in iTunes.