TML

My brother has recently moved to Oz on a 489 regional sponsored visa. He and his family have rented a house within a postcode on the list, so that's all good. When it comes to work, does anybody know if he is allowed to work for a company that is based in an approved post code, but still work anywhere? e.g work for a plumber based in Nerang (on the list) but do a job for him in Southport (not on the list) Not many plumbers would only work in one post code, so surely this is ok???? We would appreciate any advice