There are certain criteria for the referral:
- The consultant makes you a reference in the system and uploads your resume. Usually, he has to indicate why he thinks you are a good candidate
- You skip some steps in the recruiting process (CV screening at McK, Test at Bain)
- The consultant gets a referral bonus ($) if you get a job offer
So in your case, you will pass the resume screening and they will invite you to write a PST.