Is it still beneficial to take an SAT subject test(s) that's unrelated to my prospective major?

I’m considering taking a Literature subject test (and maybe US history), but I want to do pre-med. I’d likely score quite high on the Lit test at least, especially if I start preparing soon for November. Does that still look good to top colleges, or do they only care if it’s related to your major?

Do your schools even consider subject tests? Many do not. If not then they are of no help

I’d like to apply to some pretty prestigious schools that usually RECOMMEND like 2 subject tests.

Yes, even if it is unrelated to your intended field of study it is good to take. Schools want to see that you are a capable student. Just because you are choosing a medical career, doesn’t mean you can’t show a liking and knowledge to history or music. If it shows you are a good student, it will not hurt you.

SATII tests do not have to be related to your major. If you think you can do well on the Lit test then go for it.