Generally, airline programs don’t have a problem with you using your points to book travel for someone else. (Some have restrictions, though. For example, Singapore Airlines limits the number of other people you can book tickets for, and Turkish reportedly requires that the first booking you make match the name on the Miles & Smiles account). However, it's generally against rewards programs’ terms and conditions to make a reservation with your points or miles in exchange for money or other compensation. As long as you’re only booking for people you know, you shouldn't run into any problems.