You can create one or more "obligatory percentage" upsell items to add one or more sales taxes in SETTINGS-PROPERTIES-UPSELL ITEMS.
Additional taxes like city or bed taxes which a fixed amount per stay or per night are set up as "obligatory" upsell items. Depending on how they are calculated the period setting is "per day" or "one time" and the per setting can be "per addultroom", "per adult", "per person " etc.
The setting "Per Room" means the value is calculated as a percentage of the room price and not other upsell items. In this example it will not be applied to the breakfast.