I think you should share your profile in a brief to get a better answer
However...
Both hibernate and spring are hot and you will find them in all job requirements posted for enterprise applications- so you are on the right track as far as your selection choices is concerned.
IMHO- hibernate is trickier than Spring
The reason for that is- Spring by virtue of its architecture is least invasive to the code
There is little API to master.
So to code in Spring- you don't have to really code anything beyond Java
But to code hibernate- you need to know the Hibernate APIs and the gotchas of hibernate programming. The basics of hibernate are easy to master- but to learn the tricks and trivias- it takes time
If I was the hiring manager and were using hibnernate and Spring
I would rather take someone who was stronger on Hibernate rather than someone who was stronger on Spring
As far as spring is concerned- you as a contributing programmer- will have little to worry about
Most likely the application will already have a framework in place- and you will have to plug in your contributions in.
But to code in hibernate- like I said before- its better if you have soem experience on this
PS: I know everyone has a different viewpoint on this- so you maybe getting more confused .I think- once you share a bit of your profile- it will help people give you a better advice. Good luck !!!