Basically, in the early 1800s (primarily), European and American museums purchased specimens from local collectors in Colombia via some sort of clearing house in Bogota. In many cases, there was no information provided as to where the specimens actually were taken, but it is assumed that it was somewhere in the nearby Magdalena valley, Eastern Andes, or nearby Amazonian slope (e.g., near Villavicencio), as travel was fairly limited at the time. These specimens that became the types for taxonomic names had a type locality of "Bogota" although it was uncertain where the true locality was. So today, when you see a collecting locality of "Bogota" it is relatively unlikely that the specimen was actually from the immediate vicinity of the city, but rather from somewhere in the broader area mentioned above... but possibly even further afield. As a result, the collecting locality has some uncertainty, and "Bogota skin" is a shorthand way to say this.
