Never used AC when the credits apply, but the scheme is VERY slow to post transactions and very fussy about point of sale. For example, if you book via united.com and not unitedairlines.co.uk you will get no credit as they see it as buying outside the UK/Ireland. At the moment they have transactions posted up to February 2008.
You can join in more countries that the UK/Ireland via these links:
https://www.partnerplusbenefit.com/a...ramKontinent=3