tompravi Afaik wine-gecko will be installed by wine's own routine if needed for an application. At least it should offer this.
As for wine-mono you downloaded a wine-mono.msi file that you need to install with wine itself (could also work for wine-gecko if you downloaded a msi file) by entering this in a terminal
wine msiexec /i wine-mono-4.5.6.msi
You need maybe to adapt the path to the wine-mono file and the version number. This is just an example.