When you add a photo to a Circle, the people in that Circle can view it and download it. The location information described in Does PhotoCircle store the location where my photo was taken? is part of the file, so it travels with it.

Inside PhotoCircle, we don't currently display the location of a photo to the people you've shared it with.

If someone in your Circle downloads the original photo, the location comes with the file they receive, and ordinary free tools can read it. That's true of any photo shared anywhere, not just on PhotoCircle.

For tips on removing location metadata prior to upload, please see this FAQ.