Good Morning and welcome. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
It is not uncommon for cats to develop subtle issues between then such as territories and others which is causing serious anxiety for Ronnie. Since the tom cat has not responded to the Feliway, there are other ways to stop this behavior.
Have your vet examine Ronnie to be sure there is not a medical cause for thsi odd behavior. If this is ruled out, ask your vet for an anti anxiety medication such as Clomicalm....this along with the Feliway work together to decrease anxiety for Ronnie so he will relax in your home. This is very important to change Ronnie's behavior...this is given for 1-2 months so this behavior changes.
Use many litter boxes in your house in low traffic areas so each cat can find their own one that suits them and this decreases the territory anxiety allowing both cats their own space.
You may have to feed them separately at first but as the medications take effect, Ronnie will nto have any trouble with your female.
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please Reply so I can clarify for you
Sincerely, Dr. Loretta