talented at / in / for

I probably hear and read “at” more than any other preposition after the adjective “talented”:

He’s talented at music.

As you’ve noted, “for” is the ordinary preposition to use after the noun “talent”:

She has a talent for languages.

“In” sounds possible, but I’d expect to see it used before a noun that covered some large field of knowledge:

He’s talented in mathematics.

Poking around in COCA*, I found 87 examples of sentences that used the preposition “in” after “talented”. That’s not a huge number, but large enough to confirm its use:

Sixty-seven percent saw themselves as multitalented whereas 33% saw themselves as talented in one specific area.

Yue Fei, a youth talented in history and martial arts, is planning to go to the capital for the

…

…superb with equipment; not merely a good troubleshooter, but very talented in design and fabrication. “

*Corpus of Contemporary American English