"Post-Apocalyptic" vs "Dystopian" Fiction: What's the Difference Anyway?

The promotional blurb for Lioness of The Dust calls it a "dystopian" fantasy novel. I did not write the blurb, but had an experienced copywriter with way more experience than me in book marketing, do it. If he wants to call it "dystopian", than "dystopian" it is. But as I was writing it, I always thought of it as a post-apocalyptic story. So, what is the difference? 

“Dystopian” usually refers to a world where there is a clear ruling class that has privilege and civil liberties that the clearly lower class does not. Generally, this ruling class is a minority and here is where the juicy conflicts often arise. Examples of dystopian settings are found in The Hunger Games, 1984, and most of the works of Philip K Dick.

“Post-Apocalyptic” refers to a world where the infrastructure has been destroyed by natural disaster, war, or environmental catastrophe. The Mad Max movies are a classic example of a post-apocalyptic world, as well as The Road by Cormac McCarthy.

This is not to say you can find both in a single story. Or in real life.

Post-Apocalyptic + Dystopian: Syrian civil war; Afghanistan under Taliban control, Mordor.

After you read the book, I’m interested in what you think: where does the story fall, and why?