Are Longevity Amethyst, Zilina and Phantom of the Purple the same?

It's different. According to public information, Longevity Amethyst, Zilina and Purple Phantom are the names of flowers, which are different varieties. Although they may have the characteristics of purple flowers or leaves, there may be differences in other aspects, such as growth habits, flower shapes, flowering periods and so on. If you want to know their differences in detail, please refer to professional gardening books or consult relevant gardening experts.