This is hardly an American expression, but attentive viewers of the 77th Academy Awards had some exposure when Andrea Arnold won an Oscar in the short film category for Wasp, the story of a single mother living on relief. She used the phrase effusively to describe her feelings of pleasure at the moment.
The phrase turned up again in US television in 2007, again delivered with a distinct British accent. In the Boston Legal episode, “The Chicken and the Leg,�? character Katie Lloyd (Tara Summers) says to her fellow attorney, “You’re the dog’s bollocks, that’s what you are. Fantastic!�?