Finding common ground with other mom's can sometimes be challenging, but it's not impossible.
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She is very competitive sort of person. She can hardly bear someone done thing better than her.
It takes 2 have a competition. Competitive people need fuel to keep burning, so my advise is to defuse it. When you feel she is trying to one-up say very happily "well that's great I'm so happy for you" and then change the subject. When she asks about your kids' accomplishments, only give general answers "she is doing very well, thanks for asking", and then change the subject. Eventually the tension and competitive feelings will lessen and you guys will find safer topics to talk about.

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Now I am more worrying my son will lost his friends one day, he is not only just very bright, but also bossy,justice..sometimes just little too much

I not yet worry about a 4yo being to bossy or intense. 3-4yo need to explore, test, and develop their sense of self and control.
This, especially in gifted kids, can produce intense personality traits, that will most likely lesson with maturity.