[Kuruharan]

Tom had relinquished his power to dominate anything, except maybe the old forest which he already had complete control over, so the ring had no use to him, and therefore could have no effect on him.

I don't think that the two of those can go together. If he had relinquished his power to dominate anything then he did not "dominate" the Old Forest. If he did dominate the Old Forest, then I think that the Ring would have had some effect on him.

I think probably that he was such a higher order of creation than anything else in the Old Forest that he could compell the trees and creatures to obey him in extreme circumstances, but that was not his usual way. I think he probably usually left them alone.

Elrond said something to the effect that if Sauron prevailed, then even Bombadil would fall, "last as he was first". But I don't believe this. Earth, and Tom, would abide. Maybe in a form that humans would not recognize or be comfortable with, but that would mean little to him.

I have to side with Elrond on this one, but it does sort of make an interesting point. It's so much easier to renounce your control of anything else when nothing can hurt you isn't it?