Treasury Bills / Bonds Investment -help me to understand.

[dr. d]

The corporate bonds offered by different banks are the rates basically the same? or there is a small percentage difference? because right now they can only give me indicative rate.

i think the various banks get their bonds from the same source,
hence the similar rates offered to their publics.
the "small" differences are probably to cover the banks' individual background requirements.
but because we are speaking of billions, "small" isn't really small at all.