I had issues getting this game to run on El Capitan, and documented my success on another thread. Might help with Sierra as well.
https://www.pioneer2.net/community/threads/play-psobb-on-mac-os-x.2352/page-2#post-56659
I ran into this issue. I tried both WineBottler and Wineskin, but couldn't get either to work. The WineBottler version would get to character selection, but would crash when trying to enter a server. The Wineskin version wouldn't run at all.
I decided to try using wine from the CLI. I installed...