In the initial changelog about the AoL it states:
While your first minion is alive wearing this amulet, it gives a bonus of 1% per enchantment level to the strength, to-hit, and direct damage spells of your other minions.
Now if you have a +200 MH does a +10 AoL give +10 or +20 to hit. Or perhaps more/less (see below).
+20 by taking +200 x 1.10.
If it is the latter, it is a bonus to just your weapon PTH or to your entire CTH (dex plus weapon).
If it is the latter, that would suck vs evasion since +20% to 0 is still 0. No real help vs evasion minions then.