If btc market dominance goes up then automatically alts dominance go down correct?
Yup, dominance is just the percentage of the market Bitcoin holds vs the percentage of the market all altcoins added together hold.
Will we ever see another bullish run for the Alts like we already did in Spring/Early Summer and early september where alts reached all time highs?
Probably after each fork, at least until forks lose their value.
The 2 previous all time high dates for Alts are:
20th June 17, 2nd Sep 17
The above dates, what can we learn from them and how do we apply this to the bitcoin gold and segwit2x forks?
You could just use those to predict the details of another sudden rise in altcoins.
Finally when do you guys think Alts will pass the $100billion market cap and claim some dominance from bitcoin or will alts crash or become lifeless dead?
I think that altcoins and Bitcoin will continue to rise, so the altcoins might pass 100 bil dollars; but at that point Bitcoin might just be much higher.