It is imperative that your wife comes to Thailand on a 90 day non-immigrant visa because she is not at the age of 50 years she cannot change the visa on arrival 30 days to a non-immigrant visa which is needed to start the process of a retirement visa and it is also nearly impossible to obtain in the Thai consulates around Asia because your wife is not 50 years old, It is also imperative that you have your original marriage certificate with you in Thailand as this is part of the application. You do not have to deposit a further 800,000.00 baht in your Thailand bank to cover your wife’s visa because the immigration rules state that only one member of the relationship has to have the financial side so your wife shall be “piggy backing” on your current retirement visa. But please make sure that when you are ready for your wife to apply for the visa you do have the 800,000.00 baht in your Thailand bank account.