The red tail shark is an omnivore, so it could predate on smaller shrimp, so if you plan to breed your shrimp, you should avoid Red Tail sharks and, in general, avoid the addition of all fish to your aquarium for the highest yield. Because Amano shrimp does not reproduce in freshwater and is more significant than most other aquarium shrimp types, these are your safest option.
We have maintained Red Tail Sharks with adult cherry and Amano shrimp in the past without problems.