There's no strict connection between the JSE version and the
JEE version. It's possible to use JEE 5 with JSE 6, in which case you could use the newer features. You're right that the JEE 5 APIs only require JSE 5.
Note that JEE 6 is on the way into the wild, probably later this year. I don't know if it will require JSE 6, though.