We're into semantics here - some may think that 'local' refers to the company, whereas others may think it refers to the buses that they run. In the good old days, of course, both senses were possible.
But then, semantically, isn't it the word "company" that introduces the ambiguity? Is a subsidiary a "company" in the sense implied here?
This can be contentious - I did annoy the MD of the (wholly-owned subsidiary) company I worked for be referring to him and his colleagues as "not real company directors".