In all likelihood, the tree will get transplanted into a bonsai container next spring. But if the root ball is too large, it might take two transplantings to safely reduce it to its desired size. From that point on it will be treated as a bonsai instead of just a tree in a pot. I'm sure the owner will also start the process of ramification and needle reduction at that time.

Good luck!

I look forward to seeing this tree in a few years' time.