Hi cuanja,
Thanks for reaching out in Apple Support Communities. I understand that you'd like fonts you download and install on one Mac to sync with other Mac devices that you use. I can see how this would be convenient; I can provide some information. At this time it's not possible to have installed fonts sync across devices. It is possible, however, to create a font collection on one Mac, then export it and install all fonts at the same time on your other Mac devices.
If you'd like to let Apple know about a feature you'd like to see in the future, you can do so here: Product Feedback
Take Care.