Welcome to FT!
I feel for you... I was in business class on NRT-LAX and the poor FA had splashed a bottle on me. Fortunately it wasn't the whole bottle. Needless to say, my white dress shirt was permanently stained. She was truly apologetic about it.
I got $200 and I think that's pretty standard. Considering you were in economy, I think you're getting a fair shake along with everyone else. In fact, here's the post I made about it almost 4 years ago:
http://www.flyertalk.com/forum/unite...tl-flight.html
IMHO, there probably isn't much more you should be getting. A $200 voucher is enough for a cheap transcon...