Would you utilise "Using" on a member which is going to be added to a list?
No, you shouldn't use using on the object that you add to the list.

When you add the object to the list, it's just the reference to the object that gets added. There is no copy of the object created for the list.

If you use using on the object, it will be disposed at the end of the code block, which is a single statement in your example. Right after you have added the object to the list it will be disposed.

Although nothing happens automatically when you dispose an object, it's customary that the object should be unusable after the Dispose method has been called. The IDisposable interface is intended for controlling the lifespan of objects, usually to free unmanaged resources when you are done using the object.

After you are done using the objects in the list, you should dispose them.

However, from what I can tell there isn't going to be any unmanaged resources in your object, so there wouldn't be any need for it to implement IDisposable. The (supposedly) database related objects are only used during the creation of the object, and so far there are nothing unmanaged in the class.