Its a Loyalist only tech, I find that even the Advent Loyalist doesn't really have an advantage with culture. I had a planet with 4 communion centers, and the enemy (advent rebels) had also 4). I had done all upgrades culture related and yet I my culture didnt push the enemies' culture away, also there were no cap ships that could've repelled the culture. Perhaps culture is still a little buggy with the latest patch?
Edit: I also find that with 2 rounds fired at the same planet with the Deliverance Engine, I never even got a glimpse of the gravity well, the rounds just didn't do anything.