Afaik scoville only works for chilli peppers. It doesn't work for other spicy things like e.g. pepper and it doesn't work for prepared dishes either.

So you can say "This dish contains chilli peppers with X scoville", but since the amount of chilli in there also matters, that's only part of the equation. For example, a single drop of 100 000 scoville chilli pepper on a whole plate of otherwise non-spicy food might be less spicy than e.g. a dish consisting almost entirely of 30 000 scoville chilli peppers.