.genesis-club-posts .entry-title target the title wrapped in the h2 tags
.genesis-club-posts .entry-title a target the wrapped in the anchor (the link to the post)
However your theme may have stronger CSS that overrides these settings.
You can add you own custom class to each widget to allow for different setting on different widgets.
For example you could define classes mystylewidget1 and mystylewidget2 to define the background, fonts, size paddin, margins, etc on different widgets.
You would then add the classes to the widgets under Appearance > Widgets
Your custom CSS could look something like this:
.genesis-club-posts.mystylewidget1 .entry-title {
color: blue;
font-size: 16px;
}
.genesis-club-posts.mystylewidget1 .entry-title a:hover{
text-decoration: none;
}
.genesis-club-posts.mystylewidget2 .entry-title {
color: green;
font-size: 14px;
}
.genesis-club-posts.mystylewidget2 .entry-title a:hover{
text-decoration: none;
}