Coupon Restriction

In order to exempt bundles from the coupon application, you can set it up accordingly:

No: All kinds of coupons are applicable to bundles.
Exclude bundles: For auto-priced bundles, all coupons are applicable. Manually priced bundles only accept fixed cart amount coupons.
Exclude bundled products: For manually priced bundles, all coupons are applicable. Auto-priced bundles only accept fixed cart amount coupons.
Exclude both bundles and bundled products: No coupons are applicable to product bundle type.