From my limited (2 trips) bonefishing experience, I'd suggest Gotcha type flies in sand/tan, pink and green tied with a range of weights. Include some tied with plastic eyes in case the place you are fishing has very shallow water or flats covered in sea grass which you don't want the fly to sink into. The aim with the colour is to match the bottom.
As well as Gotcha/Charlie type patterns, Enrico Puglisi's spawning shrimp seems to be attractive. The ones I tied had too much weight though for Little Cayman but were good on Andros. If you would like the dressing I can post it. Might struggle with a picture as I haven't cracked photobucket yet! see
http://www.saltwaterflies.com/ep_spawning_shrimp.html.
What is the dressing for the sandeel type pattern you've tied. Looks like it might work for UK bass??
Cheers