If you are in India then you need to maintain 1600 + 2800, even if you have already got the visa.

If you are in UK[ < 1year] then need to maintain 1600 pounds for ur wife and funds for ur self i.e 800 pounds, so total 1600 + 800.

need to show 2800pounds only if you are in India.

You need to show 1600 + 800 pounds, please go through dependant guidance.