I have heard that people have carried the dried product on board without issue (both in hand luggage and hold luggage, I think) and see no reason why they should not be able to. TSA for example does not identify it specifically as a prohibited item and in the UK for example, caffeine is not a controlled drug (eg mate is available in health food shops, over the internet and elsewhere).
Airlines normally have hot water available on flights and that (in a container!) should be all your require to enjoy your mate during a flight but you may prefer to bring your own guampa and bombilla.
The trouble is that I have also heard of at least one issue with trying to take (dry) mate on board, I suspect in hand luggage. This had not been commercially packaged and I think that rather than argue the case its owner abandoned it at Security. The problem being that when loose it can look suspicious to someone unfamiliar with the product. That is hardly likely to be the case in Argentina, or for any flight departing Argentina (after all, mate is officially the "national infusion" there!), or for a commercially packaged and labelled example. In countries where cannabis is rife the reaction to mate may be different.
However this was the only instance I have heard of any problem with it and there are plenty of other examples of Security acting inconsistently at times.
I hope the above may just be acceptable as enough of an answer to allow me to add my opinion: There is negligible probability of you having any issue and every chance you will be allowed to drink it on board, regardless of where flying to or from, but only if commercially packaged. If loose your chances are not as good.