I can see value in both approaches, but I don't know if perhaps it is better to more narrowly serve one constituency deeply, or if there are parallel sites that already well-serve non English-speaking jurisdictions, for example.
This is an English-speaking site and questions must be posted in English — but our goal is to make the Open Data Stack Exchange site a great, world-wide resource for all the world's citizens no matter what jurisdiction that data covers or where that data happens to reside. So, no, questions should not be limited to English-speaking jurisdictions.
This community should focus on all jurisdictions! This is important as we look at analytics, research, best practices, and international aspects of open data. Issues like climate change, gender equality, educational performance, and human rights are essential to view in a global perspective. Whether you are on an international data-hunt or understanding how to manage open data in comparison to other nations or localities, keeping this community open to all geographic perspectives is critical.
As @AndrewPendleton pointed about, we are already evolving a set of practices to tag multi-jurisdictional content.
StackExchange is an English-speaking site, even in forums like "Spanish Language and Usage" that focus on other languages. Although it limits use by speakers of other languages, it makes answers understandable to the core users of StackExchange.
Since there's already an international Open Government Partnership between countries all over the globe, it only makes sense to have this forum include international viewpoints as well.