If your "focus" in on a new product, you better call the bundling a "sampling" campaign.
If your "focus" is on a known product, classify the campaign as "premium".
Therefore I will call "壽桃牌米線(係新出ga)買3包送一包細ga壽桃牌蝦子麵(出左好耐)," a "sampling". Because you objective of the bundle is get people to learn the new product.