Air in the fuel line will simply be vented away when it reaches the carb's float bowl. The carburetor is not an air-tight closed system.
There is always quite a bit of air in the float bowl above the pool of liquid fuel. The engine draws only fuel from the bottom of this pool of liquid.
Fresh fuel streams into the bowl through the float needle valve. The reason fuel can flow into the carb is that the bowl is vented. If it weren't vented no fuel could go in or out.
So, any air bubbles that flow from the tube into the carb will just add to the air that's already in there and, since the bowl must be vented to the atmosphere, air bubbles in the line will not matter.