The match and the candle are two different types of flames. The match is not dependent on atmospheric oxygen to initially light and burn - it is more like a solid rocket motor. But, once the fuel + oxidizer mix is consumed, the match stick burns like a candle wick. In that case, it burns less energetically in microgravity because it cannot set up buoyancy driven convection due to gravitational effects on density differences in that air around it. So, it tends to suffocate itself with its own combustion products. At least the candle does generate some flow by heating the wax and causing it to vaporize, which tends to push the wax vapor away from the candle and toward the flaming wick, and some ambient air with oxygen is drawn in to the flow. Similar to what happens in gravitational fields, but not as robust flow rates. So, the flame around the candle wick is not 'spherical" so much as half-spherical.
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