Output options using Phantom Gold

[jmm123]

Hi,
I have just bought a Phantom Gold. 
Just some questions about connectivity.
I have a choice between Ethernet,  WiFi,  Bluetooth  and Optical.

I mainly use SPOTIFY and  I can see the Phantom as an output.  Is that seeing it as Bluetooth, Wifi or Ethernet?

Is there a perceptible sound difference between any of the above.  or does it not matter - apart from the fact that I have a working connection?

Thanks,

John