I think I'd appreciate hearing that an interviewee understands that jQuery selectors are a vast improvement over getElementByName. That way they know there IS something underlying the framework, and they know enough about it to drop a function name.
I know how to put gas in the car. I don't need to know how to refine dead dinosaurs into gas.
It always better to know what is going on behind the scenes. Besides, knowledge of the language itself helps you to distinct good architectural from bad ones.
Then, even if you will use one of those libraries or frameworks, you will ultimately understand when it's best to use their functionalities and when it's best not to. Because they offers many good functionalities by writing little code, but it's really easy to overuse them, and create poor and sloppy code, while with plain JS would've been much faster.