There are many cause of air bubbles in the candle. Some simple solutions would be to heat the container and/or pillar mold. Generally a dry heat such as a heat gun or heat lamp should be sufficient, the objective is to take the chill and/or moisture out of the container. You may also want to pour your wax at a slightly higher temperature, for safety reason it is imperative not to pour too hot (not above 205 F). You may also want to slightly increase your mico or vybar usage. Finally you may want to slow down when pouring the wax into the container, splashing of the wax should be kept to a minimum.