If you are an Australian citizen or permanent resident and you are married to a Thai lady you can certainly look to take her back to Australia for a holiday or even to live there with you. Depending on your circumstances you may want to look at an Australian Tourist visa or a Partner visa. Of course, there are a number of criteria that you both have to meet to be eligible for any Australian visa, and I will go into these briefly below.
The simplest visa to obtain within this class is the Tourist visa. As Australians we often just book our ticket, get on a plane, arrive in our destination country and get a stamp on entry.
Sometimes we do need to obtain visas before arriving in a country: for example if we want to travel to Russia. Well the same applies when Thai citizens want to travel to Australia. Thailand, like many other countries is classified as ‘high risk’ (this refers to the likelihood of the visa holder overstaying their visa) and so your Thai wife would need to fill in a paper application and both she and you would need to provide supporting documentation. Being married to an Australian, in itself, will not guarantee her entry into Australia even for the purposes of tourism or to visit your family. Many things are considered. The Department of Immigration and Citizenship (DIAC) would look at other potential issues, such as the character and medical condition of your Thai wife, and her ability to be able to financially support her visit. They would also look at the length, strength and genuineness of your relationship. The processing time for a simple 3 month Tourist visa is usually about 5 business days.
The more permanent option would be to apply for a Partner visa. A Partner visa will lead to permanent residency in Australia and will allow your wife to work in Australia if she chooses. Once this visais granted and becomes permanent she will never need another visa for Australia. The Partner visa is considerably more complicated to apply for than a Tourist visa and the processing time can be fairly lengthy. However, if you both qualify, a competent and experienced Migration Agent should be able to guide you through the process and help you achieve your goal of taking your Thai wife to Australia.