I didnt go to la tomatina so I cant really give you a good comparison, but the running of the bulls is definitely a must-do thing (at least for me it was) at one point in your life.....actually I have to go back b/c I didnt actually get to do the run (long story) but if you really feel it conflicts, go with whatever feels right for you, you can always hit it up another year.
Just as a side note that's kind of cool for a female (at least I think it is~ nice little ego boost anyways) if you actually intend on running, there are about 3 guys for every one girl AT the running, and of that, I'd say 1 in 6 or 8 of the runners are actually girls....so you know, you'd feel kinda brave to want to do it, lol
If you walk backwards, you'll find out that you can go forward and people won't know if you're coming or going.
Dream as if you'll live forever. Live as if you'll die today.
Countries I've Visited: Austria, Botswana, Canada, Costa Rica, Democratic Republic of the Congo, France, Germany, Greece, Hong Kong, Italy. Malawi, Mexico, Portugal, Rwanda, South Africa, Spain, Taiwan, Tanzania, Uganda, USA, UK, Vatican City, Zambia