There are quite a bit of commands you can use with banshee, it's been a ling time now, but here's a script I wrote because I could not find a way to play a smart playlist at login.
It was months ago, it was one of my first scripts and I did it for fun so it's pretty bad, I haven't tried it since but this should at least give you an example of how usable is banshee on the terminal :
#!/bin/bash
banshee --hide &
sleep 3;
banshee --play;
while true; do
pos=`banshee --query-position| sed s/position:\ //| sed s/,.*//`;
dur=`banshee --query-duration| sed s/duration:\ //| sed s/,.*//`;
left="$(expr $dur - $pos)";
rating=`banshee --query-rating|sed s/rating:\ //`;
isHumour="$(banshee --query-uri|sed s/.*Music//|grep /Humour)";
if [[ $pos -lt "3" ]] && ([[ $rating -lt "2" ]] || [[ -n "$isHumour" ]]);
then
echo "next";
exec banshee --next &
else
echo "sleep for" $left;
sleep "$left";
pos=`banshee --query-position| sed s/position:\ //| sed s/,.*//`;
dur=`banshee --query-duration| sed s/duration:\ //| sed s/,.*//`;
left= expr $dur - $pos;
echo $left;
fi;
sleep 0.0001;
done;
exit 0;
Hope it helps, sorry if it confuses you...