WiFi not working with Sitecom WLA-3100 (MT7610U) USB dongle

Well if it runs the MT7610U there are chances that you get it going. But as it is written on the webpage you linked “USB ID not yet observed in any mainline kernel” the USB ID is not listed.
Maybe you can try to first force it to sysfs and see if it works. If that works we can see further.
unplug device
modprobe mt7610u_sta
echo 0df6 0075 > /sys/module/mt7610u_sta/drivers/usb:rt2870/new_id
plug device

Report if that makes it work