Standing meditation has a benefit of balancing concentration with body awareness. Sometimes when we are sitting there is a tendency to go too deep into concentration, then our awareness suffers. We might absorb into the object and the awareness becomes very dull, so that thoughts come into the mind and go out with no awareness that it's happening at all. We are just sort of lulling on the object. Sort of rocking ourselves to sleep, sometimes.
With body awareness in standing meditation, we can't get so deep - some people don't like that. But it is very beneficial for the insight part of the meditation; that is having more awareness; then the mind is a little brighter. It's concentrated but it's brighter and is able to see the objects more clearly. It also forces a link between the deeper type of concentration that can be developed in sitting to the broader awareness necessary for moving and walking, forming a link, a transition. Because walking meditation is a very different type of mind awareness and some people don't like the walking meditation because of this. But if they start to see this transition, it's very helpful to let go of that sitting type of mind state and go into a different type of awareness. Seeing all of these types of mind states as very important.
Another benefit of standing meditation is that it helps give us more patience in everyday life, that we can meditate in that posture and not feel that we have to go sit down somewhere (unless of course you have a problem with standing). So it helps us to be more patient, more contented in our normal life, when we're standing in lines, etc. It helps with grounding your awareness when you're talking while you're standing, very beneficial if you can get used to grounding your awareness in your feet when you're standing somewhere talking to someone and having an awareness of this body and feet. It then acts as a central focus from where you see your intentions more when you're speaking, allowing you to be more calm and contented. With a still body, there's not so much restlessness in the mind. With grounding and stillness, one can make better decisions. So standing meditation has many, many benefits. How fortunate you are to be taught standing meditation.