The rule has been changed so that you can only rescue Lost Souls in an opponent's Land of Bondage. Not that this changes the old rule where you could use Son of God and/or New Jerusalem on souls in your own Land of Bondage.
Edit: The wording is: "You cannot rescue lost souls in your own Land of Bondage. This used to apply only to your heroes. Now it includes dominants, too."
Rule change is
here
