If no one identifies it start looking for pictures of that distinctive handle. That should help you identify the company. I had a small tea set purchased from a museum store with a similar handle but have no other information.

It's so pretty, I hope you can find more. And that is a very interesting handle, I wonder if pieces with it survived. Try searching at replacements.com.

Most likely not bone china but porcelain.....and likely Japanese. Those ideas might help you in your search.
There were sooooo many patterns of porcelain tea sets made in the past 100 years, it will be a large stroke of luck if you can ID it and find more.

Probably wrong but when I was looking for more pieces of my museum store set the information I found was that the handles were made by pressing a form against the "mother" material which was in rolled sheets rather than using a molded pattern. This gave the angular shape although your look a little more rounded but that could be caused by differing glazes.