Purchased Apple Music

You can redownload music purchased from the iTunes Store using the iTunes Store app on your iPhone. Make sure both phones are signed into the same Apple ID, then open the iTunes Store app, tap the More tab at the bottom, then tap purchased.

Your previously purchased music should appear in the iTunes Store.

Redownload music - Apple Support

Do a standard phone to phone data transfer and sign in to your Apple ID account on the new phone. Be sure to check that you’re signed in to iTunes as well. Also, double check that you are signed in to the iCloud.com website, and iMessage, FaceTime, Game Center and the App Store in settings. One other place that people often seem to miss is Media & Purchases in your iCloud settings.

Your music should be on board at that point.