Even with an iPhone, you still can't sync music directly from the iPod. With Apple, music syncs from iTunes on the computer to the device, not from device to device (or even device back to computer, unless you use a third-party app).
If you don't already have the music that's store on your iPod stored on your computer, you'll need to get it there before it can go to the iPhone.
senuti has been around for a long long time, and should have a trial mode that allows you to copy a few tracks to verify that it works.