If you post on Reggaesteem.io your posts will appear in reggaesteem. If you tag jahm, your posts will appear on reggaesteem. If you make tag #hive-150047 your first tag, it will appear on the reggaesteem community. Use the tag where the tags go, not in your post.
It's new and may change but hive tags or communities are great. I always had an issue with people using 4 or 5 tribal tags. Posting in the reggaesteem hive won't get you Jahm. Tagging Jahm or posting on Reggaesteem.io will