I like the idea of the dreams being like booster shots for normal magic, although it raises a question. Can you apply, say, the Dispersal Dream's effect to a non-attack spell--i.e., could you attach it to a teleportation spell and appear in several places at once or move several people at once?
If not then you'd kind of have to wonder why these incredibly powerful Dreams can be attached to only one kind of mediocre spell--it's not as if the Dreams were created to help the spells, since the Dreams came first. The other alternative is that the spells normal sorcerors cast are merely pale reflections of the Dreams.
