DB structure for bundled products

I'm in agreement with Paul.

I'd setup the database to have a products table with a column to indicate if the product was a bundle.
Then another table with all of the products associated (and qty per product if you sell anything physical or limited uses/licenses/etc):

Table:product_bundles
product_bundle_id
parent_product_id
child_product_id
quantity
date_added

I'd actually put the product_bundle_id in the product table column for the bundled column (i.e. it is either a zero for no bundle or the bundle ID, which makes it much easier for your SQL to find the bundle's contents when you need it)

This lets you have all of the reporting and normal flows for your products and bundles using one table instead of having to group multiple tables together.