I've never heard that SH and HK banks would recruit directly from Aberdeen....Really doubt it, don't fully trust agent.
I think your decision should be based on how much you care about the 100,000RMB. If your family can afford it, go to Durham. In most cases (if not all), higher price = higher quality.
Personally, I still have lots of doubt - the job market is so tight now, and everyone is dying to get into foreign banks....I really doubt whether the bank will give preference to Aberdeen graduates, when there are possibly many other candidates graduated from Oxbridge, LSE, UCL and other American, Canadian, Autralian univ etc etc....
I still think you should go to Durham. Since you've already invested such a big amount, does the 100000RMB really matter? If you have enough luck with job, you probably will earn it all back within 1 year's working.