I assume you mean from CtA... The weapon has a plus one to all skills... What "all skills" means is ALL skills... This means that no matter what skills you have on your sorc, they will all increase by one just by having the weapon equipped... Cast Battle Command, and you will now have a plus 2 to those skills until you switch back to whatever weapon...
Again, by all skills, this includes skills that are granted by other items equipped... For example, the plus one to teleport granted by Enigma will get extra points from the +3 to all skills from HotO, from the +2 to all skills from Maras, from the +2 to all skills from HC Shako, from the +1 skills from the SoJ, BK, and Arach, and I think the +2 to all skills from the Enigma itself...
HoZ will not add to it, because it is Paladin Skills only... However, if the hammerdin was to use a Spirit shield, you would get another 2 skills from it... Teleport would then be at level 12 without Spirit, and 14 with... BC would make that level 15 for a little while...
So, you figure, the BC/BO level of the CtA is going to be boosted by the amount of plus all skills items that you are wearing when you cast it... This is why a lot of people keep a Lidless Wall shield, or a Spirit shield on switch with the CtA so as to boost the amount of time they will have a plus 1 to all skills and bigger life/mana...
In short, no... Your meteor, fire ball, etc., will not be level 21, but 22 because of the plus one to all skills mod on the CtA itself... Every level for every skill/synergy will be increased and you'll do much more damage... Factor in the other plus skills mods and you'll have like (guessing at max) 35 to all skills just from equipment alone... Add an Anni to that, and there is another point... Add a torch, and there is 3 to the class skills, but not the other "oskills"... Add skill grand charms, and that is whatever to a certain skill tree of said class, but again, not the "oskills"...
I hope this clears it up a bit for ya, and if I am wrong on any of this, please, someone set me right...
*Requiem_Death