There were different types of amphorae. There were transport type amphora, of rough ceramic, that carried wine (or fish sauce or whatever) in the bellies of ships. These would be sold by the wine merchant in town, either a whole amphora or some measure of it. Your house would buy the wine and store it in a similar, but probably smaller vessel. The transport amphora (often identified by their "Dressel" number, after the guy who established their typology) were shaped strangely and would not stand up on their own in, say, a Roman dining room -- they were designed to be stacked in racks in the ship. For serving and display, you would use a smaller and nicer type, perhaps a nice red slip serving pitcher or, if you were rich enough, a gilt silver specimen! Unfortunately, a lot of the nice Roman serving ware was silver like this, meaning meaning hardly any of it survives. Just about the only way we find these kinds of vessels are from shipwrecks.