What do the "pros" say? Ideally, your reticle and turrets would be level to each other, but in the event they are slightly (maybe not noticeable to the human eye) off, Should you level with your turrets or reticle?
It's not an opinion question. There's only one technically correct answer.
If you are shooting using hold-overs in the reticle, the reticle needs to be level to gravity when you shoot.
If you are dialing for elevation, the erector travel needs to be level to gravity when you shoot.