Fortress covenant mechanics

Does "Fortress covenant Notable Passive Skills in Radius are Transformed to
instead grant: Minions take 20% increased Damage" applied to all notable passives in radius or only allocated? For example if i haven't any notable allocated in radius but have 5 notable unallocated will minions take 100% increased damage? Sorry for my bad English.

Unallocated Notables will not give you their effects because they are, well, unallocated.
The only case in which an Unallocated Notable effect should be important is, maybe, when dealing with Tempered jewels or Threshold jewels, which are jewels that care about how much attributes are within their radius, even if unallocated.
According to PoeDB they do not seem to care about Notables changed by Fortress Covenant or Might of the Meek for the sake of the Attribute effect, but I am a bit skeptical

In your case, you just don't allocate any Notables changed by Fortress Covenant, unless for some reason you want to increase damage taken from your minion and are willing to spend Passive Point to that end

Is jewel socket notable then?

Jewel Sockets are not Notable, they will not be transformed by Covenant or Timeless Jewels

Thanks