You can get the pomegranates at the tree at the Garden Of Sphinx. There is a tree on one of those ledges. There is a sign that says "Pick it for free." You jump to the tree and it will go into your "items" bag.
On Poptropica Mythology Island How Do U Find The Pomegranate 2 Place On Hades Alter?
On top of the sphinx you will find the pomegranates Ina tree on top of the sphinx
By the tree in the garden. There is a big sign that says free. You can't miss it