The earth itself actually gets really close to the 25° you mention. According to NASA the obliquity of Earth's axial tilt varies between 22.1° and 24.5° over roughly 40000 year cycles.
There really isn't much (if any) information out there about correlation between axial tilt and how it'd influence the atmospheric phenomena you're asking about. This probably has something to do with the lack of comparable examples. We only have earth to work with.
However, Venus also has Hadley cells and its tilt is 177° and what seems to be a bigger factor is that venus has a way thicker atmosphere which makes it so it has only two hadley cells.
Another major influence on the layout of pressure systems is the land configuration on your earth. The image below shows the ideal distribution of pressures on earth if its surface was uniform on the left, and the actual recorded pressures and hadley cells on actual earth.
There are other factors that probably have a lot more influence on these patterns than a slight deviation in axial tilt, which would only make seasons slightly more pronounced. If you're working on a fictitious world with a whole new layout different from earth, it's basically guesswork what will happen where exactly, though understanding these phenomena and extrapolating the recurring patterns on earth could help you make a realistic estimation about what prevailing winds reign in certain areas of your world and how pronounced the effects are on your climate and pressure zones.
Regarding air pressure. 910hPa - 1090hPa should still be your pressure range given your atmosphere is equal in composition, density and height as Earth's atmosphere. (Mind that the values given here are the absolute extremes on earth since measurements started).
But you can deviate a little from Earth's pressures given the layout of your lands permits such circumstances (which would basically be guesswork since no data can be acquired from non-existing land).
Sources - In case you like more information on the subject.