This is pretty normal kid stuff, in my experience. After all, who wouldn't want to have everyone do what they want to do, all the time?
My DD10 has been on both sides of this, so that has been useful. Having been bossed helps her understand the effects of being bossy. It also helps that DW and I play with her A TON, and we have modeled the kind of behavior we're looking for by negotiating to do activities we can agree on... partly to work on this issue, and partly because a child doesn't benefit much from playing with a parent if the parent doesn't like the activity.
She still has her moments, of course, but she's doing pretty good on this nowadays. Ages 4-7 or so were kinda brutal in this area.
Other than that, you're dealing with an issue of managing emotions, which is always an adventure with gifted kids.
