Without wishing to sound patronising Martin- the 'three lines' as you call them that just about always surround a motif, a logo or a coat of arms (on many forms of transport- Honda motorcycle logo for instance)- they are wings not just 'lines'.
They are on the bow to symbolise a purposeful esxistence- ie. flying like the winged messenger- on business around the world.
Although I have to admit as far as stylising something goes they are pretty far removed from rlooking anything like outstretched wings, maybe if you squint...
Greg