Without seeing it or showing it to someone that knows their composites it's hard to say. Flexing the wheel slightly while looking at the damage can tell you a lot.
If you know where the damage is I'd mark the area with a little dab of something that won't wash off. Even just a little "dart" of clear adhesive tape. Then keep a close eye on the area for any signs of the crack growning outside and to where you can see it