Petra is a local wonder, therefore it makes sense for all other wonders to be local? Its not good logic. Wonders can do whatever they want, some local, some not. This variety gives the game variety. If Temple of Artemis is local only, I don't think its every worth building. Literally never. Its a balanced, already somewhat weak wonder, as it is. We could completely redesign it, or we could accept that wonders all have their own effects. One choice is clearly better in this situation.