I successfully claimed my CPL here in Australia. You are able, as far as I understand, to claim payment made for any training in your relevant field as a deduction from your taxable income. Prior to my CPL training I was a tour guide/bus driver. After gaining my CPL I went to work for a company that did tourist flights and there you have it, I had paid for training in my relevant field! My accountant assured me it was all above board but I did bump into him several years later and he said he probably wouldn't do it again!
I have related this story to many pilots over the years and am yet to meet another who successfully made a claim on his/her tax return. I trained in 1997.
CH