Ok... If you're saying that this is purely bad programming from Spotify, then I sincerly apologize for my angry message! Just seemed soo weird that all apple apps works with the bluetooth headset, but not either InTune Radio and Spotify (The only two apps I use, and the reason why I bought the watch - Music and running).
And yes, you have your apps, but don't want to pay for yet another service, so when I read that your watch supports Spotify, I think it is pretty obvious that I perceive it as being possible to use it with a headset, and then I run thrilled to the store and get one. Think this kind of marketing is a bit misleading, and I will deliver the watch back to the store today.
But again. If this is an error - or mistake - from Spotify, I am sorry for filling your ears with my bitterness.
Kind Regards
J