Bundler doesn't create any new products in your shop. It uses your existing products and applies discounts on them. This means that bundles can't be automatically displayed in collections. But you can use a small workaround to display and promote your bundles in your collections as a standalone products. To promote a bundle in your collection, you have to create a dummy bundle product and then redirect the customers to the bundle landing page. You can read more about this here: https://bundler.app/frequently-asked-question-item/why-are-my-bundles-not-displaying-in-my-collections-3.

The other option would be to use the Cartbot: Auto add to cart app, where you configure a bot, which will replace your dummy bundle product with multiple products which are included in the bundle. You can try it out here: https://apps.shopify.com/cartbot-auto-add-to-cart