Some feedback about my long layover. Definitely recommend for anyone to plan in a long layover if not few days!

Arrived in the morning. It was raining, but expecting to clear, so I took no hurry. I reclaimed my bags and took them to the end of hall where there is a baggage storage, 12000COP per bag, about 4€ for 12 hours.

Decided to avoid taxi-cowboys and Uber-hassle (if there is such), after finding a youtube post about how to grab the public bus which seemed supereasy. It was easy. Just exit terminal, clear sings for shuttle transfer to the "Portal Eldorado" with the feeder bus (green "alimentador"). Once at the Portal, just buy a loadable card 3000COP and loaded 2 trips on it, each 2000COP. Enter the Portal gate and search J6 bus with end stop at "Universidades" which just a short safe walk from La Candelaria old town area.

I did go to the Mike's bogotabiketours.com place in La Candelaria and it was a great choice. Tours at 10:30 and 1:30pm, lasting some 5 hours. There were about 15 people going and they split the group after a while, Mike taking a shorter route and Maurizio taking a longer route which I took too.
It stopped raining (they provided plastic ponchos). Bikes were quite worn mountainbikes and some of them not working properly, but the pace of biking was moderate to low so no issues there. You don't want to ride an expensive bike anyway to attract thieves.
Some notes about the bike tour:
-Mike is from California and talks better english and seemed more focused
-Maurizio is a walking history teacher and he knows the area in and out and tells long stories (good or bad), so he took us 6,5 hours in the end! But it was worth it, a true experience!
-Beware that Maurizio's way of routes and navigating in the traffic is pretty unorthodox. He cut the roads, between cars, one-ways around etc. If you are not a biker, you might get afraid but I just liked it as I am used to such biking from childhood However, he was a great guy and even if traffic in Bogota is crazy, the cars were surprisingly polite towards bikers!

Finally, the tour taking so long I did not have the time to Monserrate, nor were the museums open due to Colombians voting that day. I walked back to the Universidades station and took bus K6 back to the Portal and from there again a feeder bus to the airport. Easy and faster than taxi, since the Transmilenio buses have their own lanes so they don't stand in jammed