[Knight of Gondor]

You'll have to wait for some of the more learned to answer that question for sure, I suppose. It never seems like any spirit is entirely defeated or destroyed in the books, though the way it was portrayed in the books that Saruman's spirit looked to the West to learn his fate, and the wind that blew signaled the rejection from his reentering Valinor, or wherever the Maiar dwelled then. See, I didn't get many of my desired Histories of Middle-Earth books for Christmas! :\