It was explicitly tested with JRE 7u25 and JRE6u45 (although nobody should be using JRE6 anymore).
As far as I know it works with all instances of JRE7.
I've not heard otherwise, and it would be somewhat unusual for Oracle to change that kind of an option/behavior with a patch.
As far as which one to use... as noted in the post, the template is applicable to both architectures running the JRE7 x86 instances. So you would use the Java_x64.adm on x64 systems and the Java_x86.adm on x86 systems. Inspecting the contents of the .ADM templates will also shed some light on this. The x64 template writes to the ~\Wos6432 node, which makes it an x86-on-x64 scenario.