It applies a boost to recovery and regen in a sense that its not item-based. Your base regen is increased for both HP and SP respectively under the influence of Restoration. With the full 50 SP attribute, If i sit down every once in a while during fights, I almost never run out of SP with no SPR in my build.
Campfire and Potions do not increase base regen, they add a second regen table ontop of your base. If you notice while sitting at a campfire, you will occasionally heal your HP twice. This is because your Base regen went off at the same time as your Campfire regen. Same for Pots, they add a secondary table ontop of normal regen.
In short, Restoration increases base Regen and healing from abilities. It does not increase item-based regeneration methods. Still a really good ability as it adds ontop of the normal healing, while providing reliable SP regen during fights (Just sit for a second every once in a while).