No first hand experience, but it is entirely up to the check-in agent at GIG if he/she is prepared to go the extra mile for you and tag the bags all the way to SFO.

Do keep in mind that you should be prepared to show proof of Yellow Fever vacc. at the check-in counters because when traveling on a separate ticket to BOG, your destination to the check-in agents in Brazil is Colombia and not the US (and you need YF vacc. to enter Colombia from Brazil). I have witnessed several pax being denied boarding at the check-in counters at GRU because they didn't bring YF vaccination certificate or didn't have it.