As usual, I don’t have any firsthand knowledge about the subject. I tried a search using Chinese from Google Translate, and I wasn’t able to find anything brick-and-mortar (I don’t know Chinese, so that doesn’t mean the stores aren’t out there). My search also pulled up sites that sell things, but I wasn’t sure they sold bamboo for scaffolding.
A few years ago, there was a thread on the subject of bamboo:
I’m sorry I couldn’t provide more or better information.