The status of bitcoin is not clear at the moment globally. Some countries treat it as commodity, some as currency. Some countries ban it. So it is not a global currency yet. But it is becoming one.
It is a global currency at the moment as well because you can use it if you want from any country if you have Internet connection. It's the acceptance that can make difference in the future if the merchants will start to accept it. In that case it can create a demand for it and it can help BTC to become a currency that's accepted worldwide.