Interpreting the paper you linked:
a European family of four would see their annual
disposable income increase by an average of €545
per year as a result of the agreement. This figure
takes account not only of increases in wages and
other household income but also price reductions.
This means that price changes have been taken into consideration and so this income change is already corrected for any inflation. It is possible that a trade deal results in more disposable income, for a basic example see Ricardo's theory of comparative advantages.
I can't say how this figure was arrived at by the paper because no explanation is given.
The following has very little to do with your question, it is more of a reaction to what I perceive to be your anti-TTIP stance. If I am mistaken, apologies.
I find that people who don't like TTIP focus on strange things even though there are some valid critiques. The paper you linked says that the gains are a result of, among other causes, a
more aligned regulatory systems agreed
under the TTIP
Some critiques claim that the regulatory system will be closer to US regulation which favours companies over consumers. In terms of patent rights it may also not be optimal, though the effect of patent systems on long term growth is unclear anyway. I find that these are valid worries. Even if TTIP does decrease prices (which I think it will) there may be hidden costs. I don't know if there are, but I think it should be this that is scrutinized about TTIP.