I looked into a similar contract with Air China but a few colleagues warned me about what actually happens as opposed to what was advertised.
Advertised: A330 NTR Captain based in Sydney
Actual (after a lot of digging) A330 'Captain' but flying in the RHS, based in Beijing for a minimum of one year, possibly 2, but in any event a non determined period until the Chinese deemed you suitable for the LHS and then you could apply for what was available.