Of course, Bitcoin can be a world currency. However, Bitcoin is not valid in all countries. But seeing the popularity of Bitcoin,it will be the world currency for a time.Only the bitcoin has been known in all the countries, which could not make any other coins.Everywhere they are Bitcoin,world Currency Will be.
Bitcoin can not be a global currency. It rules the crypto currency and is not recognized on some parts of the world. Of course, not everyone will consider it as a global currency not unless it is in the virtual world.