This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
I do not think integrating Hibernate and Scala should be any different from using hibernate in Java. Scala is just another language that runs in JVM like java. Of course you cannot use scala specific features when calling Hibernate Class as those are still in Java. So my feeling is that do how you normally integrate hibernate in a java application and use scala for your own business logic