it's a little hard to tell how good the bamboo stuff is without a tds (at least I couldn't find one).
But considering that it needs more resin I don't think the equation still works out.
These days there are quite a few manufacturers marketing "green" epoxy resins, meaning that usually around 50% of the ingredients are based on non-mineral oils.
To be honest, if you really wanna go green, don't build a boat at all ;-)
on the other hand building a boat out of wood, glass and epoxy will still be way more environmentally friendly than buying a glassfiber boat that's been shipped from china. So, at the end of the day it doesn't really matter what you use as long as you use the bad things sparsely.

cheers,
Matt