MBA programs are generally looking for various types of "excellence" in their programs.
These include not just analytical excellence, but also creative, socio-cultural, cross-cultural, entrepreneurial or charitable excellence - many of these things are much less relevant for tier 1 consulting firms.
Having said that, if you're concerned that your career progression in consulting (and hence, likely your analytical excellence) coming from a tier 2-firm may not be projecting sufficient excellence to your profile for a top MBA program in the US, that may very well be the case - and I agree on the point that RB as a non-US firm probably has the least awareness of those tier 2 firms you mentioned among those programs.
However, your application to the top MBA programs will be judged based on the personal "mix" of excellence that you as a candidate bring to the table:
- What else, beside your career, is special about you and your story?
- How does this story match with the values the school your applying to is projecting?
- What exciting plans do you have for the future after having received that prestigious degree?
Believe it or not, these questions matter a LOT in getting admitted to the top MBA programs - I have personal experience from receiving admission letters from 5 top MBA programs in both the U.S. and Europe - and by the way, I only joined consulting after my MBA ;-)
If you're keen to discuss your application to an MBA program, shoot me a message.