Hey I asked this question last week and i found an answer. The answer appears to be that iCloud Music Library needs to be turned off to successfully sync the playlists. I did the following to get it to work.
1. Disconnect phone from laptop.
2. Under Phone Settings > Music. Turn OFF iCloud Music Library. Close Settings and reopen to confirm the changed setting saved. If not (it didn't for me), power down the phone. Then repeat and the setting should save.
3. Connect Phone to laptop and launch iTunes.
4. Go to Phone on iTunes and then Music. You should see the old iTunes Music screen which allows you to select playlists, etc to sync.
5. Sync phone
6. Check on Apple Music > My Music > Playlists. Old playlists should be accessible.
7. Under Phone Settings > Music. Turn ON iCloud Music Library. When you turn on iCloud Music Library you will be asked whether or not you want to Merge your playlists. Select Merge.
This allows me to use Apple Music and my playlists appear on my iPhone.
Hope this helps someone else as well.