Those would be a subset of a 4 phase system.
I prefer the use of 'antiphase' for systems where you have two lines that are 180 degrees out of phase with eachother: that's most indicative of what's going on.
2-phase can mean various things: actually having access to two phases and a neutral, which can be useful for motors and such. Or just having access two 2 phases only that are 120 degrees from eachother compared to ground, but with no neutral wire so only the voltage between those phases is available to you.
The latter was actually used in the transition from 110v-ish to 220v-ish networks in europe, where the phases each had 125 volt or so with respect to ground, and the voltage between them was about 200 volts.
This was not ideal though, things like 110v lightbulbs would burn out quickly on the 125 volts, while 220v appliances didn't quite get full voltage.
Such systems still exist in very old areas, afaik there is still a small part of amsterdam that gets about 220 volts between phases but no ground connection.
