What location data will an Android phone provide to an iOS device that lacks GPS? Will my iPad 4 Wi-Fi only (or an iPod touch) get live location data for navigation purposes if I connect to an Android mobile phone that is enabled as a Wi-Fi hotspot?
When you tether an iOS device, it will have a live data connection and perhaps make some better use of any Wi-Fi signals that are in range for determining location, but in general - you won't get GPS like accuracy just because an iPad or iPod is connected to a phone (android or iOS) over Wi-Fi tethering.

Just like your computer can't really gain GPS data from a Wi-Fi router, the same holds for an andriod based Wi-Fi router that happens to be a phone.

There is no reason why this data couldn't be sent to an app and a GPS server could be conceived on Android or iOS to provide streaming data, but this isn't something that comes automatically or by-design from Wi-Fi tethering.