The Emirates lounge is the nicest lounge at T4 in JFK and possibly the only one after security
I could be wrong, its been a while since I flew out of T4 but I remember it sort of like TA or B at EWR. Meaning the term has more then 1 concourse and thusly only those who will actually flying on a plane out of that particular concourse can gain admittance to it.
So if Im flying on Taca which uses the most right Concourse and EK I remember uses the most Left = no way for me to get to the EK club
Also sort of like SQ @ SFO I can get into it even w/o flying SQ but they are only open a couple of hrs before each of their flights then Close Up!Same with LH wherever they fly into if its their own Club
So the OP will have another problem depending on whom they are flying if any club will be open