I'd use the mboxTrace debugging tool to see what is returned for your IPs for domainName and then adjust your audience accordingly. Here's the help doc on using the mboxTrace tool: Troubleshooting Content Delivery. You'll also need to get the auth token (described in the doc). You can find it in Target > Setup > Implemenation > Generate Authorization Token.
Then load the page where Target is implemented and open the developer tools > network tab to view the mbox request response. In Chrome it will look like this:
Also, if you know other specific IP addresses that you want to include you can use the "&mboxOverride.browserIp=X.X.X.X" debugging parameter to spoof Target into thinking you are coming from a different IP and thereby see what it's domainName is too. Just add that parameter to your page URL (use a "?" instead of the "&" if there is no "?" in your page URL). Hope that helps.
It looks like you have to include the mboxOverride.browserIp parameter to get the GEO data to show in your trace. I hadn't realized that before. You can use your own IP in the mboxOverride.browserIp too.