I have asked this question many times over the years, have the taxi fares gone up? I have been charged more than the posted rate that is on this site.

No, no taxi rate hikes have been authorized. But they will continue to charge higher fares to anyone who looks like an out-of-towner if you continue to pay them instead of knowing the fares and telling them so. Also, if you take a taxi from a sitio instead of hailing one on the street, they are allowed to charge more for some unknown reason, as is explained in my Taxi Rates section.