Hi Anton,
1. Yes, you can put 2 vandas in a basket. Make sure you put them in a basket large enough to accommodate them for years. Keep in mind that vanda leaves tend to be long (from about 6 inches to about 24 inches...total); roots will grow out of the basket. They get long (lengthwise), too.
2. If both have the same culture needs and close in size, yes.
