There's definitely an interest on the island in Mexican food, and Ponce is a relatively sophisticated town. In our little barrio around Caguas we have both a street stall with enchiladas and a higher-end place that is "Mexican-inspired." Other than the latter, I've really not tried any Mexican food since I know it WON'T compare to what you can get in Mexico or even in Chicago.
Some Mexican chilis are available, esp at Walmart: jalapenos, mostly, also poblanos and chipotle. A variety similar to habanero is locally grown and made into a sauce hot enough to sear my skin. All this I don't understand, because food here is generally not that spicy.
Oh, and flour tortillas are available, but not of corn.