you dont get taxed on ctc or at least you are not supposed to.. you get taxed based on your basic salary.. cost to company includes benefits that the company provide you with.. also your contribution to the pension fund should be paid from your basic salary otherwise its not your contribution and a company benefit.. when doing tax returns based on that, you will find yourself in a world of hurt with sars.. i say this from my experiences thus far and i do stand corrected on all points..
my salaries had always been per following example:
There is nothing tax-efficient about these allowances nowadays. They are all taxable. One possible reason for showing them separately is that, in a unionised environment these are often negotiated separately from the basic salary or CTC.