The flare is there to keep the short hose from the fuel filler neck to the vet tube from slipping off.
Your filler neck should look like this
Just inside your filler neck on the top of it there is a piece of metal welded in that creates the vent line to the tube. This is the end inside the gas tank, fuel goes in on one side and air goes out on the other. This tube end is rotated 90 deg in the photo