How do you perceive Tom Bombadil?

[Inziladun]

Originally Posted by Pitchwife

Basically, he reminds the willow that it's a tree and admonishes it to behave as behoves a tree instead of waylaying innocent wanderers - and because "Bombadil is talking", the willow obeys. So, is Tom's superpower ontologic authority? Because he is who he is, can he make other things be what they are?

The Willow is clearly more than a mere tree, though. He's described as having a "grey thirsty spirit" that seems in line with Ents, or more closely, Huorns.
It obeys Bombadil because, at least in "the bounds that he has set" (to quote Gandalf), he is Master. I think he is allowed such power because he himself has set a limit on his influence. Tom wants to be left alone to pursue his own ends; he has no desire to extend his power to cover the "Free Peoples".
It's interesting that Tom tells the Hobbits:

'Tom is not master of Riders from the Black Land far beyond his country.'

(emphasis mine)

That suggests again that Tom is only so powerful in his own small place, and that was the way he wanted it.