Cursory glance, you aren't currently in the mix for MBB: non-target school, good GPA but not sure how good that really is in said school; work in a mid-size company (so neither huge brand nor startup); no real leadership experience (unless you just haven't told us)...
Best bet is probably to go back to a target school for a Master's program; it does NOT have to be an MBA. No matter what you do, MBB / Tier 2 would likely make you start from the bottom, "2.5 years of experience" is nothing as far as they are concerned.
As to where you'd land, this is a tougher question, and will probably change by company. I get your desire to not do IT/Tech work necessarily, I was in your shoes too and once said no to a Tier2 because they only offered me IT consultancy, vs. Strat consulting. At the same time, a case can also be made that getting into the company is the most important.
Boutique is always an option, but they type of role may differ (more technical, less varied). Regardless, a master's degree will usually make it easier: where there are senior partners at MBB who only have an undergrad, they are largely the exception that confirm the rule