The off-the-shelf Super Interactive Maps plugin is using Google GeoChart API, unfortunately the zooming buttons and functions are not available in this API by Google as per link here.
However, the only way we can add zoom at this moment is using CSS and JavaScript functions that will zoom existing map provided by Google.
Important Notice: The source map is coming from Google and the quality of the map is subject to Google improvement and will be out of our control. We just add this zoom capability using CSS and JavaScript.
In Patch 1.8, you will have the option to set Map Zoom to Yes when adding/editing maps via the administrator.
When the Map Zoom is activated, at frontend, your map will have a zoom icons at the bottom left which lets you zoom the map using CSS. You can also pan and move the map using your finger on PC, laptops, mobile devices and tablets.
In addition to this, patch 1.8 introduces an option where you can set HTML tool tip content at admin settings page.
If you set this option to Yes, now you can use HTML content for your tool tip when adding/editing Locations for a map.