If you want to check MTN bonus after you top up your MTN line from a VTU terminal, you can dial *559*4# on your MTN line. You will not see the MTN VTU bonus if you dial *556# or *559#.
As at the time of publishing this, MTN gives 10% bonus to customers who recharge via Virtual Top-up (VTU) and you can use it to call any mobile network in Nigeria. So, if you buy airtime worth of N1,000 via VTU, you will get N100 bonus.
Using USSD codes for airtime purchase ( eg GTBank 737 code) or mobile apps (eg FirstMobile app) are ways you can buy airtime and get the 10% bonus.
