I don't know about Coinomi but HitBTC is displaying incoming BTG deposits as pending after 1 confirmation and accepting them as clear funds after 6.  At least, this is the intention.  They are having some trouble and a couple of times now I've seen a transaction reach 3 confirmations before it's even acknowledged by HitBTC and take 9 or 10 to clear.

Also bear in mind that Bitcoin Gold blocks have been slower than 10 minutes each on average over the last 12 hours.