Twatted by a bus…

Do you have a copy of the CCTV or know that a copy will remain intact?

Go as official as you can. Report to Police as you might need a Police report number if any insurance companies get involved.

This^

Sounds like the driver is aware that they screwed up. Also sounds more like a momentary glip in attention, than reckless driving. But still deserves reporting. Best check that frame alignment is properly fecked before filling out the insurance claim ;)