Video Sender = Wireless Modulator.
I think the RF Modulator and the Composite Video have the same resolution, but using the Composite Video and Stereo Audio connectors provides a better quality signal; just as the direct cable generally provides a better signal than transmitting through the air across town.
So if you take the TV2 Composite Output, feed it into a Composite In/Composite Out Video Sender, then I think you would have accomplished nothing more than taking a perfectly good signal and converting it multiple times to degrade it less than the ViP 622's Stereo Modulated Output signal.
Maybe I'm wrong, and there are high quality video senders that will give you the same quality output as the original input.
If your other TV is EDTV or HDTV, and you are looking for a second HD signal to feed it, then maybe you should look into another receiver, maybe a single tuner HD, like the ViP 211.