I was in Majorca last week and noticed the fizzy drinks like Coke and Fanta werent so sickly sweet as they are in UK. Are they deliberately made less sweet in hot climates so they quench your thirst better? When I god back to UK and took a swig of Coke it was far more sweet and I didnt enjoy it as much.
Also noticed in Majorca the only sugar free drink you could get was Diet Coke. I’m not complaining because I hate Diet drinks but is there a reason for this?
I think the difference you noted may have been the type of swetener used. In some markets sugar is used while in others it is corn syrup.
No it wasnt corn syrup - I have been to USA and I hated the soft drinks there because of the corn syrup - it has a distinct taste which I do not like.
I have no idea if sugar content (measured in Brix) varies from market to market but I kind of doubt it. I can tell you both carbonation and brix are controlled within very narrow limits.
One thing I have noticed is that postmixed drinks often have very low carbonation.
Orange Fanta in Europe is distinctly different than American Orange soda, so much so that I would consider it a completely different soda sold under the same name.* They also make a lemon soda that is quite delightful. – Coke tried to sell it in the US under the name “Citra” but it didn’t last long. 
In Bulgaria you could get an orange soda that was just like American orange soda, called Mirinda. It was made by Pepsico.
However, I have never noticed a taste difference in Coke itself (having drunk it in Spain, France, England, Bulgaria, Hungary, Slovakia, Germany, etc.) except for the minor taste differences of sugar vs. corn syrup.
They have Mirinda in Mexico. I used to work at a Pepsi plant there and used to drink tons of it. I remember having my breakfast cereal with Mirinda _
On a similar note - is the Diet Coke in Continental Europe (“Coke Light”) actually different from that in the US? My subjective opinion is that “Coke Light” is sweeter than Diet Coke.