Atheists, question about human tails and evidence for evolution?

With every animal that has a tail, the spine extends the bone into the tail. When the vestigial gene gets switched on in rare cases that causes a tail to develop in humans, does the spine extend into it (bone tail)? If it doesn't then creationists would be right and it wouldn't be a tail. I've seen the photo on talk origins, but I wanted to know for sure.