Yep, that's a switched power line, only on when the ignition is on. There should be a 10 amp fuse in the fuse box for that. If not then add one, but don't go higher as the wires are sized for that load.
See HERE for my post on adding a much less expensive (compared with Honda's kit) 12v socket to the right pannier using this cord/connector. I used the same pins as used by the factory to fix up the dummy plug for my needs. Your other thread indicates you put a socket in the pocket for your GPS. That should do it for you.