As you can see, Star Alliance is the largest of the 3 alliances and is very strong in the Americas, Europe and Asia but has no domestic service in Australia. Most people are members of several Star Alliance programs so they can take advantage of local credit cards and promos and also the more lucrative promos with United. Avianca/Taca has several 100% buy miles bonuses throughout the year and less frequently an even more lucrative share miles promo. I am a member of United, Singapore and Avianca/Taca. The main reason for joining Singapore Krisflyer is because my Aussie Amex MR points can transfer 1:1 and they are good for redemptions on NZ, but on most of their Asian and European partners will attract a very high fuel surcharge. Buying miles on Avianca/Taca is a great way to get cheap business class or economy awards when they have a double miles bonus promo. United is a partner for Chase’s Ultimate Rewards programs with several credit cards that can accrue miles for sign up bonuses.
These links are also good if you want to check out an airline’s route map to see where they fly, join their frequent flyer program and see what you can do to earn miles by flying on partners, staying in hotel partners and patronizing their other partners such as credit cards, shopping malls, phone companies and survey companies.
This is a just a very brief overview of Star Alliance and there is so much more to learn. The best source of information is on FlyerTalk where each airline has its own forum, most forums have wikis or “read this first” posts to get you started. I will be going into some programs more in depth as the subject relates to building your ecotourism dream trip