Howdo OM
At some time you must have removed the squid from the water, and all of the water drained from its mantle cavity.
It will not die - it will eventually get the bubble out itself (it will thrust around in the water and look quite awkward doing it).
Don't touch it - just let it look after itself.
Make sure you do not have an airstone in the tank - one that is releasing millions of tiny bubbles that will get inside the bobtail's mantle. Get an airlift in there REAL QUICK (as described in an earlier thread for your squid tank).
Cross your fingers, toes, arms and legs, hold your tongue to the left, keep your right eye shut, go do some weeding in the garden, clean your room, and when you're done with all of that the squid should have come right.
Good luck.
To feed it, make sure you have some amphipods (~ 5mm total length), or small shrimp (about the same size). NOT TOO MANY in there, because the shrimp will end up attacking the squid (try 5 shrimp to begin with, and keep a VERY close eye on them - use your left eye). If the squid shows no interest in these food items after a couple of hours (either amphipod or shrimp) then you'll have to find something else; I would not try small fish - I'd try some other small crustacean first. Keep on trying with different food items until you see the squid pounce and eat - then get lots of that for a couple of days and slowly add them to the tank as the squid eats them. After a week, if it is still alive, you might like to try the shrimp and amphipods again (or other food items it initially rejected). A change in diet is good for them.
I have had quite a lot of bad experience with flounders and cephalopods in tanks together; the flounder mouth can expand enormously, and the little things have eaten many a small squid in the past!! Keep that horrible animal away from your squid at all times; move the flounder and goby to the small tank and keep the squid in the larger one. When moving it from one tank to another always have it in a cup or bowl of water.
Make sure you do a 1/3rd water change every day for your squid (if you haven't protein skimmers etc. handy).