How to transfer iMessage texts from Mac to iPhone?
Yes, you can still sync them through iCloud. Try the following:


If possible, make a Time Machine backup (no troubles expected, it's just good idea to make a backup of important info that you have only in one place);
Enable iCloud sync for messages on Mac;
Leave it charging and on Wi-Fi for several hours so messages could sync.
Enable iCloud sync for messages on the phone;
Tap "Merge" when prompted;
Leave the phone on Wi-Fi and charging so messages could sync.