My guess is that he wants to hook up two amplifiers to two subwoofers, with one subwoofer per amplifier.
In which case, you would run one power wire from the battery to the trunk, and then use a distrobution block to split the power wire to each amplifier. You could also use y-splitters to split the RCA's from the output on your headunit to each amplifier input. For the REM wire, you could either use a relay to connect them (depending on how many other things the REM is connected to), or just splice into the REM wire to split it to each amplifier. Ground wires...you could either connect them both independently to the chassis, or wire them back through a distro block to a single wire that connects to the chassis.