I've got the wishbones in vinegar at the moment to remove any bits of rust in the pits and it's doing a great job but I've kept the bushes and crush tubes out. Will they be okay if I submerse them overnight in vinegar whilst they're still on the wishbones?

You have just got to watch you don't get any little chips coming off them, lol

It would concern me leaving rubber in mild acid for 8 hours, if the bushes are poly you may be safer but you won't know it's safe or not till it's to late

Yeah. They're poly bushes and stainless crush tubes. The whole lots in a plastic bucket at the moment and that hasn't suffered.