Good question, I think the loyalty points will be added only after your friend's attendance at the match is confirmed. But when it comes to 'purchase history', I'm not sure whether they'll be eligible once the transaction is made...or have to wait until after the game as well.
15 LP is a decent return for an away fixture. An extra incentive to buy tickets or not, hopefully more fans will be encouraged to buy one. I know I am, especially as I can avoid the travel disruption in London. I'm just bearing in mind finances with potential Cup ties and other League fixtures I...