Greetings, @summer2!
Congrats on the protection bottle- it is beautiful! 
As for the exploding part, I’m assuming it was just the smoke that had a reaction and not the candles themselves? If it was the candles, there’s a discussion here about exploding candles and safety you could check out.
In terms of reading smoke and flame for magickal meanings- yes! There are many possible ways to interpret it. I’d go with gut instinct first- if you feel it symbolizes a successful spell casting, then that it most likely what it means. Great job! 
For other possible interpretations, there are lots of candle and flame reading resources in this Of Candles and Flame Challenge Post. You could also read through the following candle guide:
Hopefully these resources can give you some additional insight in possible meanings in your candle smoke. Congrats again on your lovely spellwork, and blessed be! 