This question is only about Bolivia, but I'm actually interested in other countries as well (Australia, New Zealand, Thailand, Philippines, and more). Should I ask a similar question for each country (seems weird) or should I make the question more general (what countries allow driving a motorcycle with only a car licence). The last option seems reasonable, but I also think it might be too broad. Any ideas on this?
Much depends on how the question is phrased. If the answer required is a sentence or yes/no for each country, then you could ask for a larger list. If a substantial explanation is required, then a country-by-country seems to be better. Still, if you are interested only in a small set of countries, you could just list them all explicitly. In your case, I think you can do just that and get away with it. Phrasing along the lines of "which of these countries allow riding a motorcycle without having a special license" should be mostly okay.
Otherwise, you could ask for the countries in a particular area (i.e. South East Asia, Australia/New Zealand, Central Europe, North America, etc.) as long as the number of countries is sufficiently small.