One question .... xanthum gum on pasta sauce really ?
Sorry but to me its a cop out , i have made fresh sugo from scratch using real tomatoes and let is simmer to boil for 4 hours <_< their are simpler ways if you want to thicken something. Especialy since xanthum gum is tricky if you dont have prior experience with it ( it can make things gummy , or too thick )
As stated reduce the wine before hand......
Dissolve corn starch in water and add to sauce , keep mixing until you notice a change in constistency that you feel is ideal for you.
Less then a table spoon of cornstarch may be enough (since i dont know your measurements)
Regardless though i dont see why you cant just let the sauce simmer on its own , and concentrate those natural flavors....
Simmer the sauce and let it be , occasionally mixing it.
I was trained by an italian chef , i have no problem in letting a pasta sauce simmer for an hour or 2 if its going to make it taste better , whats the rush , it not like you have a dining room with 150 people to feed.