Spine has officially supported Phaser v3 for 2+ years. Now that Phaser has a v4 release candidate, Esoteric Software brings you spine-phaser-v4, the official Spine runtime for Phaser v4.
You can now choose between the new spine-phaser-v4 or the older spine-phaser-v3. Both provide the same API and the documentation is the same for both. Be sure to check out the spine-phaser-v4 examples that have been ported to Phaser v4.