I have a membership set up and I want to allocate several of those membership pages to a bundle as a separate product.
Question: If I just create the new bundle and then give one of the pages access rights to the bundle and the membership, at different days, will that work?
Yes - the bundle and the membership level can each have their own drip content schedules and they won't conflict.
Keep in mind, If they have both the Membership Level and the Bundle associated with their account, they will get access from whichever grants access to that content first. So in your example, if they are on the "Elite Membership" at day 22, and then choose to add the bundle "The Seven Keys", they will get access to that page/post as soon as they are done adding the bundle.