hmmmmm... the only two things I can think of are:
Scottish Darien surviving and somehow expanding... it would however be blocked by the New Kingdom of Granada that already existed so it would, at most, cover OTL Antioquia, Choco and Panama... and maybe Costa Rica... then, somehow, make Scotland still become one with England and there you go...
a Seven-Years' War esque where Britain curbstomps Spain so badly that it can decide what to do with her Colonies... the would surely take the Rio de la Plata viceroyalty, and maybe New Granada... of course, in the early-mid 1700s that's not that easy...
wait, another idea
the US is unable to establish the Monroe Doctrine or just doesn't go for it... the new Latin American Nations soon become another scenario of the fight between the European Powers, and, eventually, a Protectorate of Colombia/New Granada (depending on if Colombia breaks up as IOTL and if as IOTL New Granada adopts later the name), with some luck ending in a similar status to Canada by 1900...