If you want to get bonus on glo line, you must opt in for the Glo Overload promo. It is the current glo promo as at the time of publishing this article, which gives glo customers bonus airtime for calls and free MB for internet browsing.
The code to migrate to Glo overload is : *200#
Once you dial it on your glo line, you will be on Glo Overload.
You will get instant 400% bonus airtime on ALL recharges of N200 and above and 200% bonus on data plans of N2,000 or more. You can check the bonus by dialing *122*7# on your glo line.
You will be able to use the bonus for onnet voice and SMS from 10pm to 8am during the period of bonus validity for the denomination recharged. You can use the FREE MB to browse 24/7 during the validity of the subscribed data plan.
You can read more about Glo Overload here.
Enjoy it while it lasts.