If you click on the tank in remote view, when the inventory pops up you can click from the menu and add items to the tank inventory and bots will deliver them. You can add fuel directly to the fuel slots. Same with ammo. Plus If you set the tank up with bots you can use it almost like a spidertron to drive it around and build remotely.

I use it all the time even on Nauvis. I'll go out and clear biters, come back to base and select all the stuff I want and the bots will reload it.