Many years ago, bought a Charger with white interior, dirty & a couple stains like the OP's seat.
I tried a few things in graduating order of attack, ended up with Wesley's whitewall cleaner.
Worked a charm, but if I got too aggressive with it, seemed to want to melt the vinyl texture.
Not sure on leather, though; at the least, I'd follow up with some leather treatment.
On another car, with light grey leather, I had an area re-dyed; still perfect 18 years later.