Product Bundle combines CG-Widget entity, stored on CG system and holds bundle's settings, together with Shopify product entity. It means that when you create a bundle you also need to create Shopify product as part of bundle settings. The product entity replaces list of one or more items in users shopping cart, having probably a price that is less than the total sum of line-items when purchase alone.
Use the General Settings panel to define the basic settings of product entity. Once you set title, description and price you can click the "Create Product" button. This will create a product in your store.
Once product entity was created you can use the "Update Product" button, to apply changes to product in case there are changes. For example, if you change the price in the bundle settings, you need to click the update product in order for product entity to update too.