Sometimes making it public can inspire others to do similarly. Some people don't like the fame, prefer obscurity and being happy with one's own Kamma. There's a tradition in Thailand of actually making every donation public so that other people may be able to take Sympathetic Joy with one's Generosity. This is a very common tradition so people are used to saying the word "Anamotana." (What good action you have done. May we take joy in that good action.) So depending on whether you want to give others the possibility to take joy in your actions, if you think the people have the possibility to do that, then it's ok to make it public, again with the right intention not to sort of say, "I'm so wonderful, look how generous I am." More with the Sympathetic Joy to show your Gratitude or your Compassion for a particular thing, and perhaps inspire others to do so. Yes, it gives the possibility for others to thank you also, and if possible they can give Sympathetic Joy in your Generosity.