AMP version of threads are unaffaced by vBSEO on my setup. I guess you are tying to make vBSEO powered AMP threads. It will require some edits in vbseo\includes.
You currently have two canonical tags on your AMP threads. Remove the one in ampthread template. Check my second post, edit your pagenav template.
Finally, you should remove <base href...> tag from your AMP threads. I think it is added by vBSEO, too.
You must see the "
AMP validation successful." message in your developer console log.
http://pnwmoto.com/amp/2425.html#development=1
Example:
Attachment 155444