I strongly doubt your TV will "pass-through" multi-channel audio to the sound bar.
Connect your sources directly to the JVC using toslink and use that to select the source sound. Video selection will still be done via the TV. That should give you the maximum SQ of which your units are capable.
If you like, you can connect the TV's red/white audio outs to the corresponding input on the JVC. This will pass an analog stereo signal to the JVC. It may not be the ultimate sound, but it may be more convenient for day-to-day operation,