There is no definite published list (as far as I know), for the simple reason that the locales list might change even in minor version updates.
The closes you get to such list is the Language Support section of the iPhone technical specs:
- iPhone 4
- iPhone 3GS
- iPhone 3G
- iPhone 2 is actually missing this section
If you want the definitive list of languages and locales supported by specific iOS version, you should write a simple program that uses NSLocale::availableLocaleIdentifiers to obtain the list, and NSLocale::componentsFromLocaleIdentifier: to extract the canonical codes (or the corresponding CFLocale).
