I've just joined BAEC and am a man on a mission to achieve gold status within the year. I've got a couple of 160 TP trips around Europe lined up followed by SE Asia in October and New Zealand in March.

I've just received an email from BA offering double Avios on the next flight I book within 45 days. Can somebody assist with a couple of queries:

1. I assume that everyone gets this offer shortly after joining. Are they regular offers or is it a one off for new joiners? If I don't book within 45 days might the offer get extended?
2. Is the 100% bonus calculated on basic mileage or is it calculated after addition of cabin and tier bonuses?