Tom Bombadil and Goldberry are very interesting characters and one does wonder if Tolkien was going off course in his narrative structure. In this forest we are not sure weather the malevolence is of its own accord. Does Old Man Willow act out from his own or is he in league with the Dark Forces? Debatle, at best, but I think this chapter is very necessary for a variety of reasons. One, that it states that nature is not necessarily good nor evil, that it is. Two, the Hobbits encounter what lies outside of the powers of whom they have known. Third, with regards to enchantment this piece begins a basis that will lend creadence to such creatures as the Ents and the Druedain (Woses).
Much has been debated about who Tom is and what he could have been. In essays that I have read he is seen as both a nature spirit and an unamed Maia. Historicaly Tom has resonance in such folk lore entities such as the Green Man, Jack-in-the-Green and The May Queen, The Green Knight, and of course Pan. What is unique to Tolkien is that while he did use the themes of other traditions he was not adding to or embelishing a pre-existing myth. This was his creation colored by recognizable bits of previous enchantments, but he created his own vision of what elves, dwarves, and other other worldy creatures would populate his Middle Earth.
When Frodo asked Goldberry who is Tom Bombadil she replied, He is. Our echanted forest now has someone who really is at home with such a landscape and has mastered it without dominating. His sing song approach to the world is much in keeping with tricksters who know the peril of the world, yet continue on thier way and succeed by virtue of their cleverness and prowess.
In the Adventures of Tom Bombadil we see him encounter both floral and fauna, as well as a barrow wight. Notice the lack of malice in this piece, nature is just what it is, beautiful but not without peril. At the end of his adventure he wins the heart of Goldberry and leaves her mother sighing on the river bank and the barrow wight crying.
For the Hobbits to encounter Tom is essential to the narrative because it shows them that while the powers that propell their mission are grave, there are older and equally potent earthly powers that are also at play. As we shall see in the next chapter the One Ring is of no great importance to Tom, and his statement that Frodo's hand would be fairer without it is all that we need to know about Tom.
As we continue our reading notice how Tolkien will be careful to illustrate significant past events into the narrative. Tom articulates a Middle Earth that is primal and while it is true that Suron's devilry would prove to be Tom's end, he is not the Master of Tom.
Believe and you will find your way
a promise lives within you now