Is a franchise obligated to follow the rules of the corparation, or are they considers a seperate business?
The franchise I work for only has maybe 15 employees, but the corp office the owns the name employs hundreds, am i covered under maternity leave?

It would depend on how the franchiase is connected to the corporate office. Some are separate businesses; some are considered part of the corporate business. There's no way for us to know. Have you asked the corporate headquarters?