So are there restrictions what a hobbyist can do in regards to taking videos from drones, posting them on the internet in the public domain?
If the club provided a signed document that it was a 'private donation' by you as the
hobbyist and there indeed was no money exchanged, it's not a commercial business contract. If you received any compensation from them, ie.. free membership to the club, perks or otherwise, then all bets are off.
Many people have businesses which the IRS considers a hobby.
When the IRS Classifies Your Business as a Hobby - TurboTax Tax Tips & Videos
Where is the line drawn in the distinction of what is a hobby by one government agency vs. another?