Suppose work A is clear science fiction or fantasy, and work B is not. Would it be on topic to ask about whether an on-topic aspect of A influenced a part of B? For example, would it be on topic to ask whether The Karate Kid (the Ralph Macchio movie) was named after the Karate Kid (the Legion of the Superheroes character)?
That's what the influences tag is supposed to be for.
See for example What is the first mention of Star Wars in a hit song? and Did "The World Set Free" inspire the creation of nuclear weapons? These seem to be exactly what you're talking about: questions about the influence of an SF/F work on the world outside of SF/F.
See also the previous meta Synonymise [influences] and [inspiration] tags? - especially SQB's answer.
In short: if work A is on-topic, then asking about possible connections between A and B should be on-topic. It might be wise, though, to phrase the question very much from A's point of view: instead of "was B inspired by A?", ask "did A inspire B?" People on this site are more likely to know about A than B, if A is on-topic but B isn't.