The word "sanctioned" doesn't apply to American style in syllabus competitions, for the most part.
The problem with American style is that there are many allowed syllabi, and nobody knows all of them. So everybody ends up using whatever material suits them, and nobody does anything about it.
There is a very loose set of rules set forth by the NDCA, but most of it applies to the bronze level. They have also put out a syllabus of allowed bronze figures, but since they also allow figures from other syllabi, it is more or less meaningless. One must simply adhere to the rules in terms of what's *not* allowed (e.g. continuity, aerial leg actions, multiple consecutive pivots, etc), and keep the material otherwise "bronze-ish", to be considered compliant. Of course, that's assuming there's an invigilator present, which happens at about 1 out of every 20 or so competitions.
As for your Viennese Waltz figure, which sounds like a Shadow Reverse Pivot with a hop, I've never seen it in any syllabus I've studied (though I haven't studied all of them). Nonetheless, there's no reason anybody would not allow it in Silver level or above. In reality, nobody would bother calling you out in Bronze either, although technically it's out of category both because of the reverse pivot and the hop.
Me... I've never been a fan of the hop actions in Viennese. I just think they're outright goofy, particularly when accompanied by an extended leg, and I'm not alone in this opinion. There are some people who like them... Our own U.S. champions have a couple of step-double-hop-with-extended-leg actions in their Viennese. They're the kind of dancers who can make literally *anything* look cool, even stuff the rest of us could never pull off. But to my eyes, even they look goofy while doing this move. So even if you're "allowed" to do it, the question I would ask is, Do you really want to?
:)
Regards,
Jonathan
