The Temple to Bacchus at Baalbek, Lebanon

Bacchus is a rather insignificant figure in The Chronicles of Narnia, but he is unequivocally there. Lewis presents him as a cute, rollicking Narnian. Lewis draws from the specifics of Greek myth when describing the entourage of Bacchus (maenads, Silenus, etc.). The point I would make seems painfully obvious — Bacchus is a pagan deity who (like Baal) represents all that Christianity despises and seeks to overthrow. There is nothing even remotely Christian about favorably including such a figure in a book or series of books which hopes to present an analogy for Christianity.

The following scholarly overview of the worship ritual of the god of wine can be found here:

The core ritual associated with the worship of Dionysus [Bacchus] was orgiastic, meaning that it involved states of trance-like ecstasy, “outside-of-oneselfness,” merging with and possession by the god. It was celebrated every two years, at mid-winter near the time of the solstice, on barren mountain tops, especially Mt. Parnassus overlooking Delphi. There were three parts to this ritual:

Oreibasia (mountain dancing): To the accompaniment of flutes, drums, and cymbals, the worshippers, particularly women, danced themselves into ecstatic trances.

Sparagmos (tearing to pieces): In these trances they caught snakes and small animals and dismembered them with their bare hands.

Omophagia (eating raw flesh): By eating the bloody flesh of these animals, the worshippers became one with the god and with the wild natural forces that he represented.

These facets of Dionysian ritual are woven into many myths. For example, the poet Orpheus angered some maenads by rejecting all women, so these women dismembered him.