You can install Samsung Wallet even if you're in unsupported country, you just have to change your device's csc although you may still not be able to add locally issued bank cards but you can add the international ones (supported by Samsung Wallet). On the other note, I already got the Samsung Wallet app and added all my IDs from Philippines and it's working great. I can add boarding passes from flights as well but only from Emirates, Korean Air, KLM, Ryanair, and Air France because these are the airlines which is supported by Samsung Wallet.
