A:Answer After reviewing the JBL I'm guessing that you're interested in placing the soundbar too far away from the tv for included cables to reach. I suppose your plan is possible, but it doesn't seem likely.
The Rocketfish connects the usual way: pos/neg wire set for each rear surround speaker...so four wires total for the transmitter and four for the receiver...that is, four wires into the transmitter and four wires out of the receiver. If the JBL connects with two pairs of pos/neg wires, then it would work, but I suspect not, based on the write-up online. You'd be losing the HDMI connection option, which offers better sound fidelity by far...as well the functionality of syncing and volume control, maybe even sound tailoring.
As for wire length, greater length means more signal loss, which equates to lower max volume, but also lower fidelity...not a small concern. You can offset greater length by using higher quality wires,..low oxygen, multi-stranded, gold plated terminals. Ultimately, it's a matter of preference, what you're willing to accept.
Remember, a chain is only as strong as its weakest link, so if you have great components that you paid many dollars for, don't limit them by applying a cheap connection.
