In general, what is the quality of the phone's internet connection while on your Wi-Fi? Does web browsing work okay? As I said, streaming radio isn't particularly demanding. See what results you get if you run the Speedtest.net app.
+1 for Pandora here. I've had Pandora Plus for quite some time and it's 6 bucks less per month than spotify. I stream constantly in my car and at home using 3G, but I have unlimited data with my carrier. I'll find out how it works with 4G when I get my iPhone 6 tomorrow. Now I need to find a couple of good lightning to 30 pin adapters so I can use it in the Mini and Suburban.
It shoes a full meter while connected to the home wifi, but I will check out the channel settings. That has been adjusted in the past by the cable tech support, so I may just give them a call and see if they can offer any guidance.