I am adjusting amounts from COGS to personal expense accounts for items taken from inventory by owners. Does or how does this affect the tax paid on these items?

I do not know your VAT system, but maybe this explanation will help some

first when someone takes inventory from stock for personal use, or for use in the business, use inventory adjust and the adjusting account should be owner equity drawing, or if an ltd. use an asset account as a due from [name] account, and lower the qty.  If the stock is used in the business use a business expense or asset account as applies

That will show you the value of the adjustment.  That value is subject to what we call use tax.  Use tax is the same as sales tax it just called out differently.  So, if you normally sell the item subject to sales tax, then that item value is also subject to sales tax.