Yep.. you need to get the air out. If it gets sucked down... you will run for 10 or 15 seconds with out oil. If that happens at full throttle... you will roast the engine.
I would clamp the bottom hose, and take the hose off the bottom of the filter. Then hold that end up, to push the bubble out. Then (if you are careful) let the oil flow as you put the hose back together. That way, you wont' have to re-bleed. Regardless... I would add 1 oz/gal oil to the main fuel tank. That way, if there is still a small bubble... the oil in the fuel will keep the engine healthy as it passes. I personally do that any time I service the oil system. A little extra oil is better than no oil.
