Jomtien Complex sits near the Southern curved end of Thep Phraya Road, the road you'd ride along on a baht bus to get from Pattaya itself to the Jomtien area. The Poseidon Hotel sits at the pointed top of that grouping of dark grey roofs over the complex.
I've seen this building under construction for years; worked on in fits and starts, now looking as though the base work is completed but still a l-o-n-g ways from being finished - especially by Thai construction timetables, if there actually is such a thing. As you can see, it makes a big footprint on the complex in the adjusted satellite image below. I put a green "x" on the structure's ample rooftop.
There have been rumors about the place over time; Tesco-Lotus, Friendship Market, Tops Market - all have been talked about, but that seems to be as far as it's gone. There's a rental office on the ground level to the far right, but that's about it. As you can see from the panorama picture up top today, it's almost completely vacant. Almost, other than an art dealer and the odd stall set up at street level on the corner at the far left in the photo.
My guess is that the other "Nightlife" establishments have been an impediment to finding a keystone store to take the space, but it is Thailand - so who knows? The continual additions to the area high rise by high rise may well create enough of a marketable demand to make it a desirable location.