klarius Does it matter what order we OB as to how trade routes are allocated? i.e. if we OB with Askoa first does that maximize the chance of us or him establishing a trade route (now or later) between our city and Bombay?
Nothing to do with sequence or anything. The game allocates the best possible trade routes by just going down the list of cities. And BTW trade routes are not bidirectional. If we have a trade route with Bombay, Bombay may have a trade route with Cuzco instead, if that gives more income.
Ok, why you asked is probably because of another piece of folklore that trade routes would have something to do with religion spread. Nope.
Just trade connection is necessary for automatic spread.
Open borders does not help except to let missionaries in.