Does garage keepers liability fall under the broader category of Commercial Liability?

Yes, garagekeeprs is part of the typical commercial insurance policy package, along with business auto general liability and property coverage, among others. Garagekeeps covers the commercial exposure for vehicles left in the insured's possession (which would be excluded under the general liability policy's auto exclusion) and usually has both comprehensive and collsion elements. For example, a vehicle left at a body shop or for an oil change.