The reason that it's "for" is that "snooker" uses the plans or "snooker consumes the plans". Without snooker, there are no plans. These are, we could think, "snooker plans". This is why we say, "Any plans for snooker?".
"Any plans of snooker?" This means, "Are there any plans that come from snooker?" So "plans of snooker" means the plans belong to snooker or come from snooker. This is not the intended meaning here, and therefore this one is wrong.