I'd noticed this bush for a few years because of it's shape but back then it was less than a meter high. This lot is directly behind mine and I'm often over there chasing ant nests that love my Ivy. The next time I noticed it was because it was suddenly a tree. Suddenly being something like six months but also many months without rain and nobody waters it..
Hugo passing by noticed a neighbor harvesting the berries and he asked about them. She said they are Arandanos (cranberry), are medicinal and she makes an "agua" out of them. I tried a couple of the red ones and they had almost no taste. Cranberries are a vine that grows on the ground or a bog .... can't be a tree.
So looking up Arandanos it seems there are 450 varieties so I guess there could be a tree in there somewhere. Then they are almost all listed as growing in northern climates, nothing about Mexico let alone tropical Mexico. Search for "Arandanos Mexico" and tons of them are being sold on Mercado Libre and are not cheap. Someday I may find out more about this interesting mystery but I'll take my time.