Socially, it does not matter for any dance type.
Competitively, YES IT DOES for the International Standard style.
My partner and I have grappled with this for years. In fact, teachers in our area cannot teach us because they don't know what the technique is for an odd-sized couple.
I am taller than my partner in heels. Out of heels, we are the same height. The point of contact is differet for us, and very, very hard to maintain. Not only am I taller, but we have different body types. I have long legs, shorter torso, he has short legs, long torso. If there ever was a more difficult, harder partnership, we've got it. Our look is different than that of a couple with a taller man and shorter lady. We look more like the Gleaves or like Massimo Giorgianni and Alicia Manfredini. Those couples manages work around their mismatched body types and were very successful. But both have been together for years and have trained with high quality coaches to make their partnerships work (I know, Gleaves are now divorced).
From competitive experience, I will say that judges do not like the look of a same-sized partnership or a look where the lady is obviously taller.
Now "The Look" is a tall, very thin man with sloping shoulders and a long neck, coupled with a tiny lady several inches shorter, very, very thin with no hips.
I've known and competed against couples with lesser dance abilities than us, but because they had such ideal body types, they were judged ahead of us. Judges automatically look at couples with the right "Look" over those who do not have that look. At a competition recently, I saw a same-sized couple, who had great connection and danced as one, get second place to a couple who consisted of a tall, thin, long-neck man with a little skinny partner who did NOT dance as one and had about a 6-inch gap between their bodies. NO contact point whatsoever, but they beat out the same-sized couple who did have contact and danced as one. Why? Because they had "The Look." and desired body types. At a recent competition, almost all the finalists in the standard events had "The Look".
To drive home the point how important height and body size relationship is in Standard, I know a couple where the wife is slightly shorter than the man in heels. They rarely made finals, especially in a deep field. But then the man dumped his wife and started dancing with a woman who is only 4'11" IN HEELS. He is about 5'10", and can literally pick this woman off the ground while they're dancing. (I've seen him do it.) Since he started partnering with this midget, he consistently makes finals. When you see them dance, all you see is him, because he towers over his partner and is wider than her. With this small lady, this man looks very dominate and effective on the dance floor. But when you see this man dance with women closer to his size or taller, he does not look that good. That tells me this man is not that good of a dancer, but because he now partners with such a small lady that he easily dominates, he can get away with poorer technique. And so can she. I've seen her cross his center line with her head and body, yet she gets away with it because the man is wider and so much taller than her.
If you are a same-sized couple and you cross over your partner's center, it is very, very noticeable. Same-sized partners have to be much better dancers to achieve a look that the judges want. It takes a lot more time and effort and good coaching than that of a couple with a tall man with a tiny lady. Mistakes or bad technique shows up much more with a same-sized couple than a couple with "The Look".
So if you don't have an ideal body match for Standard, you are in for one hell of a battle. You have to figure out what will work for you, because many coaches don't know how. You have to work so much harder. And you will see couples with ideal body matches be marked ahead of your time and time again, even those couples who may not dance as well as you do. It is very discouraging, but I am not about to divorce my partner just because he and I have mismatched bodies for ballroom dancing. Not worth it in my book.