The system no in operation, called MiBus, is more like a typical US system, but it has some strange features too. For one, as their route maps seem to indicate, the routes are only identified by names, not number - and that's in a city of about a million! And yes, they only have individual route maps on their site; there is no overall system map.
After checking on site, weirdness continued. The main bus terminal (Albrook, next to the domestic airport) and the downtown terminal (Cinco de Mayo / Marañon) are huge, and bus bays have signs with the general indicators for direction ("Corredor Sur", etc), but no specifics such as route numbers. (Hey, we don't have route numbers!). Neither terminal has a single system map or route map (or, for that matter, a map of the terminal itself) posted anywhere. Besides the route name displayed on the front of the bus, buses carry no route information whatsoever. A great contrast to China (where the board with the bus route would typically list all the stops) or even Russia (where you'd usually find a rather cryptic, but informative, route map posted somewhere inside each bus).
If you try to actually ride a bus, you'll find that they seem to spend most of the time going in loops, getting on or off highway, or into or out the Albrook and 5 de Mayo terminals. It seems that once they are out of the terminal area and on the highway or a major city street, they are pretty fast.