Serendipitous flowers

About three years ago I bought a plant on ebay purposing to be a Korean Ginseng bush, a variety of viburnum...What bloomed the following year was a rather nice hibiscus with huge blossoms (see 1st image)
Last year, I had these lovely smaller local hibiscus show up. (very similar to what my mom always called a "Rose of Sharon" bush. (see 2nd image) This year I have two of the smaller-bloomed bushes, and of course my original hibiscus. It pretty nice to have effortless gardening :-} I wonder if I can use the flower for hibiscus tea? Anyone know?