I've set a schedule for a collection. Why is this schedule not showing against the individual product?

"Schedules" are completely separate to schedules for individual products.

It's for the reason that you create a schedule for a collection, at this point the app does not know what products are in the collection. It doesn't know until the minute the schedule is run, at which point it looks at which products are in the collection and runs the schedule for each of these individual products.