Was there a connection between the War of 1812 and the colonization and making of a port in South Africa by the British?

In a Word, no. The British saw it fit to colonize South Africa after the war of 1812 was over. In fact, the end of the Napoleonic Wars sparked this endeavor, as the French still had territory in Africa. The British had already colonized South Africa, but in 1815, right after Napoleon had been exiled to Sicily, and the treaties for surrender had been signed by the French, England declared South Africa theirs under the queen's name. So in the end, the War of 1812 was successful to the Americans, while the help they were given by the French, might just have sent the French spiraling to their own defeat.