Thought I start a thread on this... Just had one of my family's LTE SIM get a free 2gb bonus. 
Did FP send you an email notice, or can you only see it on the dashboard?
How come I never get so lucky?
Me, too, neither. 
PEW is apparently the king of the unexpected data bonus. It will be good to see if others see it from time to time, or if PEW is just spoofing us.