Here’s some advice from Irnmadn33 for Android players who can see and vist their iOs friends’ towns, but whose iOs friends are seeing tem as not having Tapped Out:

For those of you who have Android whose friends have iOS, if you can see and visit their towns but they either can’t see yours or it says to them that you don’t have TSTO, I found out that you need to make sure that your Origin account privacy setting is set to allow friends to see you. Hope this helps.

For those of you who are experiencing this issue, please let us all know whether this works.