Choose multiple products with Commerce product bundle module
It's not possible, I've had to developed my own module to allow to choose the products contained in the bundle.

I created a product reference field in the product, from that set of products the user can choose his bundle.
I created a product reference field in the list_item type, where store which products has selected the user.

My module makes possible to show as I want the products in the product display and add to the cart