Bundles are a system which allows you to offer bunches of fixed dates & times on a specific listing, for a specific price. This can be used to offer an advantageous pacakge, or simply to facilitate a more flexible format of block booking.
Bundles cannot be redeemed across appointments or group requests.
When a customer purchases a bundle, they do so by purchasing a bundle for a specific event listing, e.g. a terrarium making masterclass:
The bundle they purchase can therefore only be redeemed on fixed dates & times offered on this specific listing. So whenever you add more dates to this listing, your customers with bundles which are still valid (as you can set bundles to expire), can click through and redeem their bundles.
Bundles, therefore, cannot be redeemed across several listings - they are only vaild for fixed dates & times on the listing they have been purchased on.
However, if you'd like to accept a bundle session for another listing, and manually reduce a customers bundle, you can read about how to do this here.