Does that company have any of their paint and body done anywhere else? That may be a reason why your shop isn't honored. Even though you guys do most of it or what ever, how about the upholstery, do they get mentioned? And the Chrome shop? If they mentioned everyone "They" wouldn't be the builders at all! Wild, it's a bummer credit can't be given to who deserves it but I can see why it gets sticky.
It's all about you knowing yourself what you did and walking in there with your wife and showing her the car you did and that sort of thing. Knowing you did it and being proud, that is all you can do when the business is such as it is.
Be proud, not disappointed.
Edit, AHHHH I missed that you simply weren't in the photo while the rest of your shop was, bummer. The same still stands, be proud.