Welcome aboard Zambie.
Without knowing the specifics about your JVC head unit I would say yes you can simply tie your amp to the head unit and be good to go.
Without knowing the specifics of your JL amp I cannot say for certain every speaker and the subwoofer would work though.
Some use a 4 channel amp where the front speakers are powered by 2 channels, the sub powered by the other two (being bridged into one) and let the head unit drive the rear speakers.
If you prefer your soundstage to be from the rear use the amp to drive rear speakers and head unit the front speakers.