Sure it would be great IF it worked. The truth is it probably will work, but it won't work well. If you only want to do simple commands and you create a handful of 3 word commands that are carefully chosen, it will probably work ok. It is highly unlikely that you will be able to request media by name though. Also even trying to train windows speech with a bluetooth headset can be a long and frustrating process...
If you are ok with taking a chance, go for it. I would love to be proven wrong!