Obiter Dictum, by definition and under the doctrine of stare decisis, is never binding in the U.S. It may be quoted in support of decisions but in and of itself is not binding.
Sorry for your misunderstanding, but the Minor case as cited by Gray in WKA is an excellent example of stare decisis. The Minor decision rejected a 14th amendment claim of citizenship and instead recognized natural born citizenship for the person in question and for women, as a class. In the appeal leading up to the WKA decision at the SCOTUS, it was suggested that the lower court decision, if upheld, would create natural born citizens of those who were born in the country to aliens without those parents first becoming naturalized citizens. Gray recognized that the court UNANIMOUSLY rejected Virginia Minor's 14th amendment claims because she fit the court's definition of NBC. In respect to that decision, Gray could NOT declare WKA to be a natural born citizen and that the Minor decision categorically exempted NBCs from being subject to the citizenship clause of the 14th amendment. He thus affirmed the Minor decision and was bound to respect it by using different means to declare citizenship status for Wong Kim Ark. Ark was not declared to be a natural born citizen AND his citizenship was subject to different criteria than is required for natural born citizens.