Thanks, that sounds hopeful. Coinomi support also responded yesterday;
"Yes, as long as you have the private key that the BTC were on at the time of the fork, then you can retrieve. Just read these FAQs for more information and then sweep the BTC private key into your BCH wallet. Let us know if you have any questions."
Kind Regards,
Coinomi Support
All about forks
How to extract private keys from other wallets
Can I import a standard private key to Coinomi?
Yes. Refer this article.
https://coinomi.freshdesk.com/support/solutions/articles/29000009716-can-i-import-a-standard-private-key-to-coinomi-