Taiwan is not part of China.
Bioware on multiple occasions has stated that they only region blocked sales of the game, not access to it.
If you are being blocked access to the game it is on your ISP end and it is most likely Chinese Government rules. Heck do they even let Star Wars and Star Trek the movies to play. I know for a long time they were banned because of there subject mater ( I know Star Trek was because of its support that Time Travel was possible)