Frodo's Barrow Dilemma

[Inziladun]

Originally Posted by Gordis

On the contrary, wearing the Ring he becomes fully visible to all the denizens of the Spirit world: ghosts, spirits, wraiths, ringwraiths etc. He would also still be visible to those "who dwell in both words": Calaquendi Elves (like Glorfindel or Galadriel) and Tom Bombadil.

Oddly, Gandalf apparently could not see someone wearing the One. He certainly was from the Blessed Realm.
I would say that his being clothed in a real body may have been a factor, but why should that be an impediment to him and not Bombadil?