Nice. I have to disagree with those who think the background is too much for the bonsai. For me, without what you chose, it would be just another bonsai. The background does make the tree seem overwhelmed, but a bonsai is something very fragile to begin with. I think you did a great job of portraying that. But, as Grandpa Jake always said, "Beauty is in the eye of the beerholder."
Hope you don't mind a couple photography tips. When photographing subjects that don't take kindly to the strobe/flash, try bouncing the light from the ceiling or off a nearby wall. That infinitesimal time lag helps reduce glare.
If you can't turn your strobe to bounce its light, try this: cut a piece of translucent plastic milk or juice carton two or three times the size of your flash's aperture. Attach it to your flash (I use velcro attached to the flash attachment and the plastic) so the plastic is about an inch in front of the flash. Using a filter like this diffuses the flash so it reduces or eliminates any glare of highly reflective surfaces.
Thanks for sharing your painting. I like it.