bbPress.org

I just tested the topic tag import and everything appears fine for me.

* I created a WordPress post tag topic
* I created a WordPress post category topic
* I created a WordPress post and added the tag topic and category topic to the post
* Imported from bbPress 1.2 with topics including the topic tag topic

All results appear fine for me, I have posts/topics correctly associated with each taxonomy:
* http://example.com/tag/topic/
* http://example.com/category/topic/
* http://example.com/forums/topic-tag/topic/