Let me separate the two issues:
When you visit somebody's city you should ALWAYS have a least one hand icon over their Main Hall, UNLESS it's under construction. Clicking on the footprint of the building that's UNDER the hand symbol should cause at least your coins to increase, and your supplies as well if you're returning a visit within 23 hours. If that's not the case then you need to do the diagnostic drill, post a bug report that defines your system parameters, and right click to create a support ticket so that the Game Moderators can check it out.
When somebody visits YOUR city they have the options that BobbyKitty indicated. If you've indicated that you want your Main Hall to be buffed, or if that's the only easy thing to do, then you'll only see ONE buff but you can click on the Notifications to see who is stacked in under that buff.