I think that while it is small like it is now, it will be a secondary currency in those types of countries. People will still price things in dollars or other fiat, since those are the bigger network effects currently, that is what people earn in, that is what peoples' liabilities are denominated in, etc.

If bitcoin grows large enough and becomes far more widely held, then its volatility can decrease, and then price formation starts to look similar to how it did on a gold/silver standard. Some prices are pretty global, while other prices are pretty local. Natural gas right now in this specific city, can be priced very differently than natural gas right now in another specific city, for example. A Big Mac in one city can cost very different amounts than a Big Mac in another city, due to differences in labor rates, material costs, real estate costs, etc.