I am pretty sure it is spirea. I purchased two at the time and gave one to my step-dad. His remains a lovely garden plant with white flowers.
Mine's been cut back and cut back in various plastic training pots and a few months back I decided it could go in a bonsai pot; still a training pot but giving it some context for the future. I also decided that it could work as a root over rock. I know it is less than ideal doing a root over rock at such a late stage but the main root fitted like a glove and with the rock partially underground, I reckon it will only get better.
I am quite happy with this as a start and now the ramification process begins. Any thoughts and feedback will be appreciated because I have never worked a tree in this style (or of this species) before. I was thinking Broom style (but I think brooms start higher up. So perhaps it's multi trunk style

