Honestly, I've found that tourism doesn't really come in to play until archeology, when you can make it skyrocket, but the great works also provide +2 culture every turn for the rest of the game, making them generally better than the other options early game. While it seems strange to think about it in this way, I've generally been getting the great works early for the culture bonuses (the minor tourism bonuses are nice but not essential), and the golden ages/one shot culture boosts later for the gold and culture (when you want tourism, but the +2 isn't all that much). Concert tours are a late game thing I think when you are actually focusing on it.
Basically, great works early are nice, but mostly for the rest of game culture benefits rather than the tourism. Tourism comes in force with archeology, so as long as you have good late game culture and tech to get policies and buildings that support tourism, you can shift to a culture victory anytime.
I've also found that focusing on tourism and culture early is a losing strategy. Focus on tech first, and your tourism and culture will come in force late game, or naturally if you can get wonders from reaching the tech first.