List and store vector3 of game objects with tag

how would I be able to list and store all vector3/Transform.position of all gameobjects with a gametag

Thanks

using System.Collections.Generic;

private Dictionary<string, Gameobject> data = new Dictionary<string, Gameobject>();

This would probably be the best bet because you will probably want to find fast certain gameobjects. You can also just create tuple class wrapper and store them in list.