For this method to work, your amp has to be on the same network as your PC...it doesn't matter if it is wired or wireless.
My RX-V3900 is wired to my broadband router. I think there is a maybe a wireless module I could buy for the amp, but they are both next to each other, so just as easy and quicker. My laptop connects wirelessly to the router, and therefor the rest of my network and the web via this method
There is very, very little setup. Download Jamcast, register it...tell it the folders you want your music taken from and it will find them all very easily including flac (tested) and Ogg apparently (untested). The Amp saw the Jamcast application as a Music Server automatically and if I had known where the virtual soundcard option was the first I tried it (see instructions for Yamaha amp above) then I would have had the whole thing downloaded, installed, configured and running, streaming and Spotify in about 10 minutes tops