If it was me the money would be better spent being put towards a SoundScape C or subwoofer, but if you have the extra cash laying around then why not?
Regarding the audibility of bamboo vs. MDF, this doesn't apply to those two exact materials, but I believe it is pertinent to the discussion:
Years ago, Stanley Lipshitz and John Vanderkooy at the University of Waterloo did some experiments where they built and tested a number of loudspeaker cabinets of the same dimensions and volume that varied from being completely inert to being very flimsy with almost no bracing and thin cabinet panels. They then measured the effect of the different cabinet constructions on the measured acoustical response of the loudspeaker noting the change in frequency, level and Q of the resulting resonances. They found that the audibility of these resonances were in most cases below the absolute detection threshold of audibility for music signals using the threshold data from the resonance detection study Floyd Toole and Sean Olive conducted at the NRC.
In other words, Lipshitz and Vanderkooy concluded that you could get away with loudspeaker cabinets that were relatively light-weight and flimsy as long as you had adequate bracing judiciously placed etc to make the resonances fall below their detection threshold, which brings us back to bamboo vs. mdf. If semi-flimsy cabinets, according to this study, don't effect sound quality provided the resonances are below the detection threshold of audibility, how could bamboo make a difference? It is also worth noting the SS8 cabinets are not flimsy or lacking in bracing. On the other side of the coin, though, technology has changed since Lipshitz and Vanderkooy's study, so one could argue their methods are now dated.
Regardless of the new or old data you find, this will still remain a highly debatable topic. Due to that, go with your gut and choose whichever gives you a bigger warm and fuzzy.