YITH WooCommerce Product Bundles is an extension conceived to create bundles with the combination of some products of your shop. You can assign an ad-hoc price to the bundle or a price given by the sum of the single elements included in the bundle itself.
The integration between these two plugins allows your users to add also bundle products to their waitlist.
After installing and activating both plugins, you will be able to give your users the possibility to add out-of-stock bundle products to their waitlist.
For further details about the settings of YITH WooCommerce Product Bundles, please refer to the official documentation.