Yes I also think that bitcoin is becoming a worldwide currency and more people are interested to know about it, how they can treat it.
In addition to your answer bitcoin is slowly spreading over the world and the number of bitcoin who used it getting higher. For me I can consider it as a global currency because of its uses right now.
Technically, we can all consider Bitcoin to be a global currency since it is not being limited into a certain geographical region. Right now, in almost all countries there are people who are into Bitcoin even in countries where the government declared Bitcoin to be illegal as transactions can be done anonymously. Soon, there is a big possibility that Bitcoin can explode further and we can a big rush of new people entering into the Bitcoin marketplace.