Strictly speaking, the Campanilleros are not Flamenco cantes. In modern times, the Campanilleros have been related to the Christimas celebration in Andalucia. They come from the folklore which happened to be considered as Flamenco due to the custom of Andalucian gypsies to sing their own version during the Christmas celebrations. 
The melody itself is beautiful and evoking. The verses normally have a religious theme.