The thing to bear in mind here is that, unknown to many even here,
'Pikey' is as racist a term as "Paki" or "Nigger". In some ways, it's worse than "a Soul Food joint being called "Nigga's, not least because the high levels of poverty and prejudice against gipsy/Roma/Travellers are often worse than the latter groups mentioned.
Having said all this, if there is no British ownership, then, of course, they get a pass. In fact, even if there is British ownership, they get the benefit of the doubt as they genuinely may be ignorant of its origin and regard it as equivalent to 'chav' (almost as vile but not regarded as a racist term). However, as is often the case with the thin line between the use of racist language and racism, if they were to continue to defend their use of the term, upon being notified of it, you would have to question their motives.
To be fair, this lot seem to have done this innocently, I am sure that 'pikey' isn't a racist term in the US and, though my knowledge of US travellers is very small, I wonder whether they would even be aware of the term. I hear that you have had your own version of "Big Fat Gypsy Wedding" over there. Did anyone watch it and did the term come up?
Are you going to bring it to their attention, Inca?