No.
Google Analytics does not explicitly indicate whether the device is on Wi-Fi. If your site has a relatively low traffic level, a way to estimate the number of mobile visits via Wi-Fi and 3G would be to use the domain variable that is sent by the ISP visitor.
If the device is connected to 3G, it will be displayed as "mycingular.net", "myvzw.com" and other domains that provide mobile mobile companies with their 3G networks (and 2G, 4G, LTE, etc.). If the device is located on Wi-Fi, the domain will be displayed as "rr.com" "comcast.net" "sbcglobal.net" or regardless of which domain belongs to the wireless network to which they are connected. Depending on your traffic level, there may be too many domains sorted to find out the exact number of visits to Wi-Fi or 3G. In addition, some domains may not be clear, either Wi-Fi or 3G (for example: AT&T is a cellular and Internet provider).
To find out how many domains you will need to sort, enable the Advanced Mobile segment, go to Audience → Mobile → Browse, and set the secondary size as a domain. The number of rows is equal to the number of unique domains.