Hello currently the Priest soul link SQI bonus activates auto guard at all Priest Link levels 1 through 5. But the Energy Coat SQI bonus on Hunters only works when the Hunter link is level 5.
Edit: One more thing, there's an issue with Hunter Soul Link that makes the Sniper unable to move for 2 seconds after using double strafe. I think this was a Gravity balance for Beast Strafing but my friends have to log out and log back in to remove the soul link and keep the energy coat buff every few minutes. :/