John Bucksnort's bunker mod was just a small Spear demo set. There's much more meat here, but it feels more inconsistent as a whole... You be the judge though, I'm dumb.
There's several PC mods referring a bunker in their name, but only one called The Bunker - a 2-level release for the Spear of Destiny demo by John Doesnort. The Mac answer to this is also called The Bunker and it's a full 10-level episode for the First Encounter (of course). And what can I say, a lot of this is usual fare: maps are mostly small and compact, difficulty is inconsistent as enemy density can go from mild to insane even within a single map. Still, there's a lot of stuff to collect and kill here, so you'll get your kicks out of it regardless.
===CREDITS===
JazonP (at) aol.com