I don't think there is anything built-in, but you can do it by leaving more space above your axes and using figtext
:
axes([.1,.1,.8,.7])
figtext(.5,.9,'Foo Bar', fontsize=18, ha='center')
figtext(.5,.85,'Lorem ipsum dolor sit amet, consectetur adipiscing elit',fontsize=10,ha='center')
ha
is short for horizontalalignment
.