When dragging the map chart onto my sheet, I am not given the option to add dimensions or additional data, only more layers. Therefore I am only able to add city and cannot connect it to revenue as the "add" option is greyed out and I am unable to select it. See screenshot below.
This is by design, you only have one dimension to enter in. What is required next is adding the expression for revenue into the size and shape options. That will size the point properly and overlay it on to the dimension/location you enter.