If you expect the government to legalize it and declare it as a global payment method then I think it will not happen anytime soon or very unlikely. But if you ignore government statements, bitcoin is already essentially a global payment method. Because you can use it whenever you want without asking anyone's permission as long as you have reached an agreement between the two parties (seller and buyer).

To be fair, using bitcoin for domestic payments sometimes comes with some hurdles like fees or confirmation times, which can be slower than with banks. But for international payments using banks is quite complicated and troublesome while bitcoin will be easier and faster.