I'm going to disagree with Michal Paszkiewicz somewhat. Low tension strings will bend if a light breeze hits them. It will also be very easy to play barres and bend several notes that actually should not be bent at all.
You really need a large amount of control over your vibrato and bending technique to not make them sound like they should not. Remember when you bend notes you are actually playing different notes to a certain degree which is not always good interpretation of the music.
Now it is not all bad. A good player can add depth to his playing by introducing the very subtle vibratos that these strings can provide but that is something to introduce later in ones playing life.
I would say that regular tension strings are still the best. You are very unlikely to build up bad bending habits with them and they are strings that have some bite to them. They do not just give in at the slightest touch.
It is very much a trade off the higher the tension the harder you have to work to bend but also the less likely you are to bend when you don't want to ( and should not) versus the lower tensions where the phrasing is easier but the chance of bending when you should not or don't want to is higher.
Get your beginners to play just regular tension medium strings and when they are reasonably proficient one day get them to experiment a little.
EDIT:
I'm just going to add that string gauge and string tensions are not the same. Classical guitar strings are all the same gauge or in other words the thickness of the strings but the tensions of the strings differ. That is how tightly wound the strings have to be tuned to get them in tune.
The OP uses the word tension which implies classical guitar strings. It is not clear if he may mean gauges and electric guitar strings.