All good flies posted above. I would make sure you bring a selection of flies for all species. The good news is that many species will eat the usual bonefish flies. Use bite wire for barracuda, shark, wahoo.
Bonefish
Triggerfish
Bluefin Trevally, Golden Trevally, Barred Trevally, smaller GT
Adult GT
Barracuda and Blacktip Shark
Bluewater Yellowfin Tuna, Wahoo, Sailfish
Milkfish
Hawaiian Ladyfish
Reef fishes like Wrassees, Emperor Fish, Grouper, Queenfish
I use Christmas Island Specials (sizes 4, 6 and 8) in a variety of eye weights (plastic eyes, bead chain, small brass eyes, 5/32 brass eyes, and large brass eyes). Colors are light orange, sand, pink, yellow tinge. Polar bear fur or finn raccoon wings work well. Hooks are important, use 2X and 3X saltwater Gamakatsu. Pick your flies based on the color of the bottom, water depth, and soft presentation. If the bonefish are picky, use small flies and less weight.
Next, I would tie a selection of small (size 2, 4, 6) Clousers in tan/white and olive/white using polar bear fur, yak hair, or bucktail. Small bead chain size 6 Clousers are deadly for selective bonefish. They also work very well for smaller Trevally species like Bluefin.
I always fish tan yarn worm flies in medium and heavy weights for bonefish. These are very effective imitation of coral worms.
The Alphlexo Crab in small sizes can be good for Triggerfish, so I'd bring a few along. I do best catching Triggerfish using light weight bonefish flies that land softly and drift slowly.
Some shrimpy flies with rubber legs can be deadly at times for bonefish, and smaller trevally species will hammer them. I keep these handy if Golden Trevally or Bluefin Trevally are in the area.
Brush flies 1/0, 2/0, 3/0 sizes for GT are a must. Tie them in tan, black, purple, white, grey, yellow/red. Don't make them too bulky though. Smaller sizes are generally better for picky GT. Use top quality heavy gauge saltwater hooks. Gamechanger flies will work too. Deceivers tied long and thin to immitate Needlefish are recommended for adult GT as well.
Bring 3 or 4 green or red Barracuda flies with razor sharp hooks and stout steel bite wire. There are places in the CXI lagoon where the Barracuda get very large. Blacktip shark will eat a bonefish fly or a GT fly on occasion so cast to them if they seem aggressive (use wire). Flies that look like juvenile milkfish, mullet, needlefish, black wrasse work best for cuda in the back country preserve.
Milkfish can be caught near the lagoon entrance using green/white algae flies like "Milky Dream" or using a worm or egg fly. Usually done from a boat at particular tides.
For bluewater fishing, you need a few big double hook rigged trolling flies in purple/black and pink/white. Very heavy sinking fly lines like the Leviathon and 90 pound bite wire are needed. Also bring 100 pound saltwater swivels (black), crimping sleeves (black), crimp tool.