Maybe, maybe not. They were captured by Devastator. Vader took Leia with him to the Death Star so he could personally interrogate her. There's no way to tell whether the other crewmembers and embarked personnel were transferred to the Death Star, kept on Devastator, or delivered to an intelligence facility for interrogation. My money's on them being on the Death Star, though; what's the point of having bajillions of prison cells if you're not going to use them?