Didn't you have a specific per day expense budget? I think there is a department of labor guidance for local travel and a department of state guidance for international travel.
Usually, if your per day expense is less or equal to the guidance (where I work we do $90/day), no one cares. If you go above, you pay. The per day expense is for food. Alcohol cannot be claimed as an expense unless you are in sales.
Even in your short, simple comment I see 4? 5? (or more?) pieces of administrative policy that need to be policed, and then we need a process to handle these rules - and the edge cases (ex: what if I'm travelling with someone in sales but I'm the senior employee and we take a client out for dinner? only sales can expense alcohol but typically the most senior employee must pay), and the resubmission process, and the approve of exceptions process, and on it goes...
There was a limit but I wasn't allowed to just buy anything I wanted. I think I got up to $100 a day (not counting hotel).
I didn't expense alcohol.