Rick wants to know if he could use a Bluetooth receiver to stream music from his computer upstairs to his internet radio downstairs. Leo says probably not. Bluetooth is only 30' and it probably won't go through the floor. There would also be lag issues. That's why Leo uses Sonos to do this, and it works great because it uses DNLA.
The Logitech Squeezebox should do the job. If he's willing to use iTunes, he could AirPlay to an Apple TV downstairs that's connected to his stereo system. It would work via Wi-Fi. Miracast is another option. He'd just need the right receiver downstairs.
The chatroom suggested using AirFoil from Rogue Amoeba.