Struts does not correctly get validator msg and args from alternate resource bundles. Struts ignores a bundle attribute defined in the validation XML msg or args element tags used in the commons-validator framework.
There's already a bug in struts on this. Here's a summary,
Bug 21760 already includes a patch to go into Struts to resolve this issue. The patch is dependent on some changes in Commons Validator that are part of Validator 1.1.4. Struts is waiting for a "GA" quality release of Validator 1.1.4, then will move the Struts dependency to 1.1.4 and apply the fix.
and the details...
Unfortunately this implies that the NetUI annotations for validator msg and args alternate resource bundles will not work until the fix in struts is integrated into NetUI. User will need to keep msg and args in the default resource bundle.