Which of Jupiter's moons did I most likely see?
The galilean moons are visible in binoculars, indeed. Yesterday evening (assuming you're in the western hemisphere), 3 of them were visible as separate dots. See the chart here:

http://www.wolframalpha.com/input/?i=jupiter+galilean+moons+on+march+6+2016+at+9pm+pst

You can adjust the query to reflect your time zone, and the actual date/time of the observation.

There are also smartphone apps that allow you to determine the position of the moons at any given time. On Android I use the Moons of Jupiter app.