the following is meant for Citibank MA, not for Citigroup GICB MA....
I went for the first round, though quite some time ago (approx 3 weeks). It was an interview with the HR, and the lady asked pretty general stuff, e.g. your interests, why u chose your major etc. I guess the key is that u need to show commitment to the local environment-- they are looking for ppl who can stay long term in the singapore office. And I did not answer well in this part. I said probably I want to go back China after a few years and that disappointed her...
And I think you need to show knowledge of consumer banking as well... and of course be confident to show that u r good...