Bonefish flies can be very effective for striped bass. Flies for bonefish are commonly made to resemble shrimp, which stripers will readily eat when available. Striper-ready bonefish flies include Gotchas, Crazy Charlies and Clouser Deep Minnows in sizes 4 and 6.
Another effective bonefish fly for stripers is the the Lefty Kreh designed Shallow H20. Made to resemble a shrimp carrying eggs, this fly is a go-t0 for schooling fish in shallow estuaries.