If my product uses a certified RF transmitter, is it treated specially by the FCC?
Really the best way to get an answer to questions like these is to call your test house and just ask them, even if you are a first time customer they'll tell you things like this for free.

That said I wouldn't say you are treated as a unintentional radiator per se.  You just no longer have to do the intentional radiator testing as long as you are using the same antenna the module vendor used and following their integration guidelines.  This should save you plenty of cash on its own.