hermione:
Whether or not you would take your wife with you depends very much on your schedule. The problem for any wife in any expat situation will be how she can meet others in a similar situation. It's always easy/easier for the hubby, as he can establish contacts at work. If you're going to be out of town a lot, think twice.
Unlike other Asian cities we've lived in, we were not been able to find a club (even sports club) that has a reasonably high level of expat membership.
It might be easier if you have kids at school and your wife can meet other mothers through school activities - although I've heard that international schools in Bangalore do not focus much on sports - so no rowing breakfasts, rugby mornings or swimming pool functions.....
We solved it this way: my wife would commute in and out of BKK, where we have a house and she has a business. Two weeks in BLR and two weeks in BKK.
It might also help if you find a self-contained residential complex with supermarket and club house.