If your travel on TG a lot, then yes. Because you will be given a higher priority for waitlisted flights.

However, be forewarned that TG's Royal Orchid Plus mileage expires after 3-4 years, and that you can only redeem flights for yourself , spouse, children and parents. For other people, it's US$100 surcharge.

For other airlines' flights, other people other than immediate family cannot get tickets.