Not the same. Not sure why everyone things Costco gets these top brands to private label top shelf stuff for them. Why would Patron want to trade Costco customers to something that is so much cheaper? They may get Patron to bottle some leftovers that may be "ok" for $21, but it is not the same in any way shape or form.
Sorry I work in the industry and all of these SD on alcohol make me shake my head.
When it comes to Costco, they often require manufacturers to produce private label products for them in exchange for carrying/selling a product. Most of the hype/price of a product is marketing. Sometimes there's some minor differences.
While doing some tech work for a large bakery, I watched while the same product (bread) went from the main company bread bags, to "store brand" bags.
Apparently the Costco rep was full of it. I just went and looked at my Kirkland label, and it's NOM 1472. Which rules out Patron. Oh well, it has good reviews, regardless.