No, it's not cross platform - it's a native library, OS-specific. If you wish to distribute your resulting application as one multi-platform binary you'll have to include VLC for each and every platform you wish to support, it will get large very quickly. I'd advise against this approach.
Personally, I took the approach of building separate platform-specific installers (all still automated and taken care of via ant) and then just bundling the required native libraries. This also has the advantage that on some systems with good dependency support, the library doesn't need to be bundled at all (on Debian / Ubuntu for example, I simply add VLC as a dependency into the package's control file.