Can 4 conductor speaker wire be used to connect a pair of speakers?

Yes, you can use 4 conductor speaker wire to connect a pair of speakers that each only have 1 pair of connections. The problem with that is unless the two speakers are right next to each other (thus collapsing any hope of achieving stereo sound separation), you're going to need to cut away the outer jacket for the distance between the two speakers, which will make the setup process very inconvenient.