This interpretation of the VRA says nothing about the race/ethnicity of the actual representative, but whether or not he is the candidate of the minority community's choice. Since Bonilla's voters are largely Anglo, with Latinos voting Democrat in Laredo, he's not the candidate of the Latino community's choice.
It was a tongue-in-cheek observation (most FReepers know what a sarcastic smart a$$ I can be). Further, and and not that I at all approve of what I'm about to type, (and I'm pinging swinney the s. texan for his input), there are many many hispanic "democrat" voters in S. Texas look for an hispanic surname before they look for party affiliation on the ballot. Of course, that theory is moot if it's a Cuellar vs. Bonilla race.