Wind speed could be fairly irrelevant to the balloon-city; it will never touch "ground". If you can steer away from vortexes (assuming them to be rare), they simply don't matter as a safety issue. (Staying in a desirable temperature zone could create a need for resisting the wind, but that's not a safety issue.)

OTOH, because wind velocity is highly tied to altitude on Venus, wind farming could be an important source of energy generation (along with chemical generation for emergency demand). Drag a fan at a hotter, lower, higher-pressure altitude, and harvest the electricity. In fact, storing an excess of wind-farm energy as chemical energy could power the occasional need to steer away from vortexes.

If the problem of a chemically-inert package can be solved, floating inhabited stations could be feasible.

I hadn't considered the drag-a-fan approach. It brings to mind an interesting kind of sailing where you've got multiple wind directions to solve for. Never mind that an atmospheric colony wouldn't really have a lot of destinations besides itself. Might as well just be one big flotilla.

I expect that a more boring approach would prevail: solar panels. No need for impossibly tall airships to resist wind shear just so they could get at both sides of the hot/cold setup for operating a sterling engine.

Engineering sense aside, I still wanna know if nature would allow the geothermal approach. Something about the idea that a column of air at rest would settle down into such a disequilibrium that it could be harvested of energy in this way feels wrong to me, but I've been unable to muster the thermodynamics chops to align my head with my gut.