If it was a factor, it was an extremely insignificant factor, and correlation should not rule out coincidence. The primary factor distinguishing the Spanish from other European powers is their focus on conquering the agricultural, sedentary Native Americans. Expanding that analysis out to a slightly more meta-level, the Spanish were not keen on travelling to the New World to perform labor themselves, but to conquer peoples to perform labor for them.

In the Greater Antilles, they worked the native Tainos to death and then replaced them with African slaves.

In Mexico, they conquered an empire with an estimated population of about five million in the early 16th century. By way of comparison, the British Colonies consisted of about two million persons, including slaves, at the time of the Revolutionary War. Overall, Spain had conquered approximately 15-20 million sedentary, agricultural Native Americans. The Spanish made them subjects of the crown and somewhat aggressively converted them to Catholicism.

Disease greatly diminished the population of the Mesoamerican and Andean civilizations before and after the initial conquest, but even a reduced workforce numbering in the millions benefited the Spanish more than lands populated by nomads where Spanish settlers would have to do the labor themselves. Since the population was declining instead of growing, the natural impetus for expansion was somewhat weaker.

The Spanish did expand and settle into areas with non-agricultural natives, such as Agrentina, Southern Chile, and the American Southwest, but this expansion and settlement was considerably slower than the massive acquisition of millions of subjects at the beginning of the 16th Century.

So, basically, there were much more powerful factors at work. An argument that the location of Mexico City was chosen due to similarities between its climate and Madrid would not merit much support.

Source: The Penguin History of Latin America by Edwin Williamson Feb 23, 2010