Not sure what an Apple 4GS is. Thought apple went from 4S to 5. The problem is not the hardware regardless, it is the software. I have a 4S running IOS 6.0.1 and it works great on the Bose docking station. The issue I have is I can not get remote speakers to work because of IOS 6.0.1, even when I use splitter to access peripheral equipment. In theory Apple agrees this should work and the issue is the operating system not the hardware.
I spent about 10 hours between Bose and Apple to finally get upgraded to an Apple "guru" after they realized I knew what I was talking about. This is why I was surprised Apple did not fix error in in 6.0.1. Lucky I had iTouch on IOS 4.0 to troubleshoot and prove it did work in the past just not on the new operating system.
Also why did you copy ITunes library one tune at a time. If you attach phone to computer you can select all songs and drag to music directory on the iPhone.
Also for others out there. I just bought a ColdStream Bluetooth dongle ($30) for my old SoundDock and can send music from my iPhone to the SoundDock. Wish I had known about that before buying new SoundDock for my iPhone. Would have save me a couple hundred dollars! It works great.