Posting this here for other members and future reference...would love to hear other recommendations. We get to Detroit a few times a year.
We ended up at the Detroit Club bar and then at Shinola Evening Bar. Both had great vibe. Not much opportunity for flirting at Evening Bar -- very intimate and seating at tables off to oneself -- but fabulous lighting and mood. Detroit Club was outstanding sexy venue but was really dead that night. Would go back there and definitely recommend for others, too.