LifeinAsia - 3:33 pm on Sep 2, 2010 (gmt 0)
I think the key phrase here is "authorized representatives." If your client has a specific program that offers Google Local verification as one of its services and the customers actually opted in to that program, then I'd say it's okay. But just because a business owner adds their business to that directory does NOT make that directory an authorized representative and in my book has no authority to do anything beyond adding the listing to their directory.
Otherwise, you run into a situation where a business owner may add their listing to 5 IYP sites. Each one of them decides on their own that they are an authorized representative for that business and try to verify the listing on Google Local. That is certainly something that Google wants to avoid.