I can’t answer for St. Bondaventure. I understand he was quite the scripture scholar.
My copy of Erdmann’s History of Christianity (which is not at hand, unfortunately) says that Bonaventure recognized eight “senses” of scripture.
Currently, the Catechism of the Catholic Church describes four “sense” of scripture. I have not studied that in detail, but there must be an equivalence of sorts between these two lists.
The point being, that he is probably speaking to the “tree of life” in Genesis, of course, and he is making not a literal but some “spiritual” equivalence, inasmuch as the Tree of Life in Genesis was said to confer immortality to those who ate from it (not sure if that meant just once or continually).
Now, the spiritual sense of scripture is broken down into three parts, allegorical (symbolic), moral, or anagogical (escatological, about the end of time).
So, the equivalence of the Tree of Life with Christ is undoubtedly allegorical. But, don’t overlook that for the literal sense of scripture, that it definitely says that if Adam and Eve had eaten of it, they would have lived forever.
These “senses” of scripture are concurrent, so this tree can have multiple meanings.
The Jews, for their part, recognize the literal, symbolic or allegorical, the homiletic sense of scripture, and the mystical (do the letters and their shapes, their numeric values mean anything?).
When a symbol is used again and again, we might be pretty sure of its symbolic value. But, like my Baptist friend said, “sometimes a sword is just a sword” (not symbolically meaning the Word of God).
Christ is the Tree of Life in scripture, probably in the allegorical sense, as above. And, He is the Giver of eternal life, as the Judge of all mankind, in the anagogical sense.