I don't think the NTA or FN have officially told me about this 20% 'bonus' so how could I apply it? Also, the NTA have repeatedly said the fares on the meter is the MAXIMUM we can charge and we are free to discount if we want. So boohoo to FN if I discount. They don't set the fares and they are not my boss.
Having said that, I recently threw a guy out of my taxi for taking drugs and being blatant about it. [
The safety screen protects us...but it also protects them when I want to 'talk' to them about their behaviour 
]. Anyways, got ~70% of the fare in coins and drove up the road a bit before I pulled in to finish the 'paperwork'. FN sent me a message about the fare being too low. I wrote them back and said I fuked him out for taking drugs. After that, they were only interested in whether the amount I entered into the app was real or made-up. Oh, and they said they'd put a note on his file!