I had a valid H1B till Aug 2011 with a company X. my wife got visa till Aug 2011. company X is mentioned on my wife's visa.

Two months Back I transferred my H1B to another company Y. I got the I-797 approval till Aug 2013. But the company Y did not apply transfer of my wife's visa.

Here I have two questions:
1. Do i need to apply transfer of my wife's H4 visa, though it is valid till Aug 2011. (Even I-94 is valid till Aug 2011).
2. If I need to apply it's already been two months I changed the company- will that be any problem in the fututre and How soon I need to apply?

Thanks!