You won't be able to connect Bluetooth speakers no. The Wii U does use Bluetooth for it's peripherals but there is no interface for use outside of first party products.
If you need to get audio directly from the console you could try use the AV out on the back if you have Wii component cables laying around. You would then need to change the audio output cable config in the Wii U audio settings. I haven't tried this myself so might be worth doing some research first... should work though.