First, the term "hispanic" encompasses anything relating to the Iberian Peninsula (Spain and Portugal), and everything south of the United States border and the Caribbean.

Secondly, the term "latino" refers to just everything south of the United States border and the Caribbean.

Third, both terms refer to the culture, not the race or ethnicity.

Fourth, there are many races and ethnic groups within the hispanic/latino label. The actress Zoey Saldana is a Black latina, for example. The actor Martin Sheen is a White latino, just as the actress Linda Carter is Latina (mixed). In either cases, both are thoroughly Americanized, but their heritage are Latino.

IMO, both Kyle Rayner and Kendra Saunders are both Latinos, by heritage, whether or not they acknowledge their heritage or not. But both ARE American by culture, so, it shouldn't matter in the end.