I fear the bonus points may not be achievable. All the signs are that, basically, the allowance is whatever you want it to be, in practice. There is clearly no way whether 70cl or 1L each is going to make any difference:
Responses to a question on Colombia Connections about what the dollar allowance is for US purchases brought to Colombia before you have to start paying IVA:
coolcoil Mar 23, 2016 at 10:44pm:
It's USD $1,500 and 2 bottles of booze. In my experience, they will let you slide with 3 or 4.
gallito Mar 24, 2016 at 12:43am:
I buy my duty free booze when arrive in BOG;downstairs beside the international arrivals baggage carousel.The women there told me I could buy 8 bottles;so this last time I bought 2 bottles of rum (Botran Reserva,Solera $55) 3 bottles of wine + 1 lrg, bottle Crown Royal (Northern Harvest) I bought at YYZ duty free.
Never even asked at Colombian customs.
vago Mar 24, 2016 at 3:59pm:
My wife and I use the Attenza duty frees in PTY and BOG, and bring in up to 6 bottles each
A long time ago I was not sure about what exactly the measure "1 bottle" was but could not resist the temptation to try a rather large single bottle of Scotch (I think 4.5L), admittedly into a different country. I'm afraid nothing indicative came from my attempt as I managed to avoid Customs and Immigration (which was rather fortunate as I had another two standard bottles with me and was entering a prohibition state as a minor.)