Yellowtails are completely different that winter flounder. (see my description below)
This regulation apparently doesn't affect winter flounder.
I know recently, the yellowtail population has decreased greatly (I honestly think it wasn't ever really that great down this way anyway).
RE: the ID of a yellowtail.. Yellowtails have a very pointy nose, and their coloration is typically lighter than winter flounder. The tail is a shade of yellow.
I personally have never seen a yellowtail caught, anywhere in NJ, on rod and reel. I'm not questioning you guys (that posted above) that said you caught them in J-Bay and Raritan Bay... Of course it's possible - but catching them on rod n reel is tough. And catching them "inshore" is tougher, since they like colder, deep waters surrounding wrecks.
You will see lots of winter flounder with orange or yellow rings around their tails and on the outsides of their outer fins - there is a reason for that (I honestly don't remember!) but those colorations are pretty common especially in Raritan and Sandy Hook bays, as well as on the S shore of LI.
I attached a great pic by Capt Jason Colby who runs flounder charters up in Boston, where they do come across yellowtails occasionally. You'll notice the difference in a regular winter flounder as opposed to a yellowtail
