I have a similar setup (Hibernate + Struts + other bits).
I am tempted to answer 'no' to your question. Hibernate and Struts are each pretty much totally oblivious of the other.
Each is a tremendous piece of software, and they happen to work well together. But I think if you choose to go for Struts, you'll do so on Struts's own merits, regardless of Hibernate.
(Given your pre-existing setup, I would be tempted to suggest you give a serious look at
Spring, which is completely modular. You start by using Spring's ORM component along with Hibernate, and as you go, either Struts provides the MVC framework or Spring does. Only thing with Spring: steel yourself for a flourish of acronyms and lots of talk about "Aspect programming"...)
Now, I am fairly novice with all those questions: only four months of experience. So, don't rely on my comment only! Good luck!