I will answer as a fellow Australian - it is winter here at present so if your ganache is NOT firm at room temperature now then I am assuming that your ratio could be well off unless you are in the far north tropics.
I know a lot of Americans advocate chilling of cakes but from my experience and fellow cakey pals - it more often than not leads to sweating issues here.
Your ganache should be really firm to the touch - ie you should not be able to press your finger into it - at room temperature (by that I am saying average of 21-23degrees C) if your home/environment is warmer than that then you will need to consider air-con (an absolute essential) if you want to decorate with ganache in the Australian summer)
Air bubbles WILL form and your fondant will become sweaty and sticky, often making it difficult to even run your smoother over.
I don't suppose your are using the Bakels 'ganache' from the bucket (or decanted by a cake decorating supply store) because if you are I;d say this is 100% of the problem.
Try leaving your ganached cake (at a ratio of 2 parts chocolate to 1 part cream) to firm and set up at room temp - in the warmer months this can take up to 12 hours,
Once firm - you only have to give a light brush with either sugar syrup or water - make sure it is a LIGHT but even cover over the ganache (do this BEFORE you foll out your fondant) and make sure you run your smoother all over the cake to make sure there is contact everywhere - of you miss a patch this is where your air bubble will form
Oh and the cake decoraters BEST FRIEND for air bubbles these days is an accupuncture needle - they are fantastic and don't leave ANY marks at all - they will make your normal needles look like crowbars!
Hope this helps