SkeletonBounds is only for bounding box attachments, sorry. Most characters have many region attachments and checking them all for hit detection is often overkill. Even games where hit boxes are very important, such as Street Fighter, use rectangular hit boxes that don't necessarily match the character images.
You could simply add a bounding box that matches the region attachment, then you can use SkeletonBounds.
Or, you could put a bone in the center of your region attachment or character, then at runtime get the world X/Y of the bone and use it as the center of a bounding circle. It's very easy to check if a point is within X distance of the bone.
No worries, your English is fine!
