Browsers are fine with this but it doesn't change the fact that your document is invalid. Don't rely on such behavior to construct your pages. You never know that they might choose to break it in future versions.
If you're going to have multiple elements with a same "identifier" anyway, why not use a class instead of an ID? The jQuery selectors to use aren't very different:
$(".Genders", "#tableFor_SEARCH").buttonset(); // Or $("#tableFor_SEARCH .Genders")
$(".Genders", "#tableFor_CREATE").buttonset(); // Or $("#tableFor_CREATE .Genders")
