iPhone localisations (or is that localizations?) do not take any notice of the Region the user sets (ie, UK, Aus, NZ). There is only one "English" language translation available by default. However, you can hack around with things to force it to use a different translation setting - I've just done this for choosing between "English" (US) and "en_GB" (British english).
In your main.m file, alter it so it looks something like below (put in your own tests for NZ or AU)
int main(int argc, char *argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
// Set up the locale jiggery pokery
NSString *language = [[NSLocale preferredLanguages] objectAtIndex:0];
NSString *locale = [[NSLocale currentLocale] objectForKey: NSLocaleCountryCode];
if ([language isEqualToString:@"en"] && [locale isEqualToString:@"GB"]) {
[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObjects:@"en_GB", @"en", nil] forKey:@"AppleLanguages"];
}
int retVal = UIApplicationMain(argc, argv, nil, nil);
[pool release];
return retVal;
}
This pops the users language (eg "en") into the language NSString, and the users locale (eg, NZ, GB, AU) into the locale NSString. If they (in my case) match en and GB, then I set the users default language preference settings to be "en_GB", then "en".
Then, in your application delegates application:didFinishLaunchingWithOptions method you want to remove that NSUserDefaults setting you just set with the code
[[NSUserDefaults standardUserDefaults] removeObjectForKey:@"AppleLanguages"];
It's safe to remove at this point because all the bundle initialisation has been completed. Your app should now be using a Localization.strings file within the en_GB.lproj directory.
It's a bit of a horrible, hacky solution, but it works for me.