White fluffy bun from dim sum steamed pork or sweet bean buns?

This is my second attempt trying to make these things. Last night I used a yeast dough recipe but they came out having a somewhat gross offputting cheese flavor. I think it was from the yeast. And they didn't come out looking like the above picture.

I used AP flour, milk, yeast, sugar, salt and let it rise. They were not tender, fluffy and white, they were grey and they had a "skin" on them like a soup dumpling which I'm guessing because the water from lid dripped down on them (I did wrap the lid in a towel but it didn't seem to help because it created a tent that caved in on top of the buns. I used a metal pot and not a bamboo steamer since I don't own one.

Is it cake flour or a special flour that should be used? Bleached? Or rice flour? I bought rice flour from Patel Bros but I was told I bought the wrong one (should be glutinous rice flour and not rice flour -- for mochi ice cream).

A lot of recipes call for bread flour which I don't have but that doesn't seem right because it would make the dough elasticy like baked bread and not delicate and tender like in the restaurants or picture. I put white vinegar in the water. That's didn't do anything except give a vinegar essence.