Although it seems logical (the strings are not connected directly to the mahongany) i don't think that is a correct assumption.
Given that the wings are properly jointed and glued, the vibrations would transfer from the bridge to the body the same as it would if they were a single piece of wood.
I'm sure wood density, weight, (and maybe porousness) in the wings have their effects on the vibrations of the wood. An instrument with no wings would surely sound less whole than one with wings?
Saying the wings have no effect on the tone would be similar to this scenario:
Say you have a neck 5 pc, maple, ebony, bubinga, walnut, mahogany
The neck would no doubt produce a distinct tone, but it is highly unlikely (has anyone tried this?) that playing your b and e strings produce a completely different sonic sound than the a and d strings just because they above a different sort of wood.
I could be way wrong, I'm just trying to be logical...