What I'm looking for in an API is convention and some common set of rules. As long as the API has an understandable structure and good documentation, I'm happy.

The first case would be preferred if the API is for e.g. general queries of companies in some region. The second case might be preferred if your API only deals with those specific companies and has a different structure for each one (for good reasons).

You can also provide both APIs - one for general data, and one for specific details.