Is it possible to change my wearable device voice recognition language? Most of my message recipients don't know English, so I text them in Spanish.

Now I have a wearable device, but can't seem to find how to make it recognise Spanish when I dictate to it.

Is it available at all? How can I change it?

I tried setting the whole watch language to Spanish but it still only lets me dicate replies in English.
Unfortunatelly, the Answer is No. You can't switch recognition language in progress.

But you can switch default recognition language for entire phone (and wearables at once).
Launch google search app. Go to settings-Languages and check Spanish and English languages there.
after that TAP AND HOLD on Spanish language and then Save.

This will force your android device to recognise Spanish language by default.

Additional info from 2015 Summer:
You still can't set you default wearable language separately from your phone. But it looks like Android Wear finally started recognise not only your default phone language but your additional phone language(s) too. Thats pretty cool IMO.