I don't think that there were any Madrid's at the Alamo, because if there were there would be a county in Texas named Madrid, just like Bowie Travis Fannin and all the others.
I also grew up in El Paso and San Elizario. My father's name is Lorenzo F. Madrid; my grandfather was Lorenzo C. Madrid, my great grandfather was Bonifacio Madrid, my great great grandfather was Luis Madrid, and my great great great grandfather was Gabriel Madrid. I am searching for my g-g-g-g grandfather's name. This would have been sometime around 1800 or before. San Elizario was part of New Mexico part of New Spain.