it would be great if you can implement ajax add to cart on single products page for all products. I contacted the support of Woocommerce product bundles plugin regarding ajax add to cart and got this answer:
“However, this is not something that we can implement on our side, since AJAX Add-to-Cart functionality is not provided by WooCommerce core in single product pages we have no way to add support for this feature.
Because this is a feature that is embedded in your theme, it’s your theme that needs to add support for custom product types such as Product Bundles.
Checking whether a product instance supports AJAX Add to Cart functionality is rather straight-forward and can be done by calling $product->supports( ‘ajax_add_to_cart’ ).
Feel free to share this with your theme author(s).”