The number of watts per gallon don't matter as much as how far from the light the anemone is. You can have a 20 gallon, or a 2000 gallon tank, but if the anemone is 3" deep with a 96w light he's getting the same amount of light. That seems to be a little on the low side, but the anemone would probably survive. It would really do well with more light though. I had a LTA in a 55 gallon with 2 55w PCs and 2 40w actinics once that lived for a couple of years, so it can be done.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety -- Benjamin Franklin