OP says you just scan the QR code of your passphrase from Electrum, but that doesn't work in coinomi
I didn't say to use your passphrase. I specficaly mention to use private keys.
is there any way to get electrum passphrase or private key to a coinomi wallet?
Yes, there is. Just let your electrum to show you the QR of private key and scan it. But if you are using segwit address (begins with 3) it will not work.
or could I take the private keys from electrum and import them to new BTG wallet?
This is also option but requires you to download BTG blockchain ... which I found unnecessary for most users.
my electrum wallet has 162 private keys.....is there a faster way than adding them 1 by 1, or is there a way to figure out which private key has the BTG on it?
I udestand my way is unhandy for claiming coins from multiple addresses (not my case, I have tracked where my BTCs were before the fork happened and then swept only those addresses).
I'm pretty sure there is an option how to claim coins from multiple privatekeys (using your wallet seed) but I don't know the specific procedure. If somobody is aware, feel free to share it and I will update the OP.