In my area of the state there are several smaller impoundments that are loaded with largemouth bass. During the summer I go out on a friend's boat, I flyfish and he uses spinning gear. I had my best luck subsurface this year with a wacky rigged Senko type bait. I think its made by Yum, its a french fry looking thing with air pockets on the bottom side. It sinks slowly, maybe an inch or two per second. I let it sink for a few seconds then strip it back in an erradic motion, stopping now and then to let it sink back down a little bit. It kind of moves like a large Zara Spook topwater plug, except underwater. I also had decent luck using a 14 to 18 foot level leader made from 6 or 8 lb Trilene, with a jig and pig style lure. I fished it just like you would with a regular spinning rod, flip it out and let it sink to the bottom then just bounce it up and down around submerged cover. It's tough to feel strikes with the jig, but if you pay attention to the leader, its not all that hard.
Has anyone tried using regular poppers for bass, like the Zara Spook's, with any luck? I imagine that they are probably harder to cast because of the weight. One of my favorite flies to use as of late, for smallies and such, is a Clouser minnow with the curly tail from a Mister Twister slid down the hook. The tail usually only lasts for 3-4 fish, but they are not very expensive to replace. I do get some wierd looks when I go to the local sporting goods store and buy a bunch of fly fishing and tying stuff and then buy a pack or two of Mister Twisters.
I did find a good use for all of the old bass Jigs I have, though. I have probably 20-30 jigs that I will probably never use again, and just the other day I started tearing the skirts apart so that I could use the rubber material as rubber legs for Stoneflies and such.