Cayetano Romo de Vivar and Maria Josefa VAllejo

Cayetano Romo de Vivar and Maria Josefa Vallejo were married (date unknown) possibly in Jalostotitlan, and at least five children baptized there:
Mariana Josefa Bernardina, c. 27 May 1786
Maria Josefa, c. 7 Jan 1795
Antonio Mariano Martin, c. 24 Feb 1785
Jose Alex, c. 26 Jul 1789
Maria Antonia Dorotea, c. 9 Feb 1793

Does anyone know who the parents of Cayetano and Maria Josefa were?