Do you shy away from certain woods for limb wedges?
I'm wondering if Ebony would be suitable?

Can't say about ebony.  I try to stay away from woods with a very open grain, seems they tear and chip easily.

When I put a wedge on a wood tri lam I normally am only concerned with adding thickness to stiffen that area, so if it's suitable for use anywhere else on a bow I have no problem using them as a wedge.  I've used ipe, coco, yellow heart, and a few others, but never ebony. 
Not sure about glass bows, but the concept should be the same. 

Ive used ebony many times it works ok . I have it in my personal bow .

I like to use wood that matches the riser in a take down. So if it is good in a riser should be good as a wedge. being between core and glass should be fine. edge would be best.

Same as mike , if it's good for risers, should be fine in a wedge. Edge grain if ya can ...

Thanks everyone. I'm building the riser out of Desert Ironwood and have plenty for a wedge but was looking for something to serve as a bit of an accent in the limb between the boo. I'll play with it a bit and see what I think looks the best. I'm building this bow for me and it's going to be a pretty one!