#1. "RE: No autofocus w Tamron 90mm macro" In response to Reply # 0
I'm assuming that your Tamron 90mm is one without a focus motor built in. If that is the case then it wouldn't have any AF with the FT1. If it is the newer model that has a focus motor it may not work even then. It seems that third party lens support is hit and miss with the FT1 adapter.
#3. "RE: No autofocus w Tamron 90mm macro" In response to Reply # 0
I have the Tamron 60mm macro and it will not focus with the FT-1 either. It tries to but ends up hunting incessantly. I would guess that since Tamron has to reverse engineer their lenses that some functionality may be missing with newer products (such as with the Nikon 1 system).