I know more about trees than I do about making bows (which isn't saying much really
)
Sapele is in the same family as mahogany, and somewhat similar apparently, but as far as I can tell it isn't a proper mahogany, but as has been mentioned, that is probably an advantage because mahogany isn't a very good bow wood.
Sapele looks like it might be much better as a bow wood. If you look at the density, elasticity and strength, it's about the same as hard maple. But then again woods within the same species can be very different depending on lots of factors.
I'd say it might not actually be too bad (given it isn't a proper mahogany if it's Sapele.)