Onion
If you paid by credit card, the extra cost of replacement flights is a consequential loss and yes you are covered. It will probably be better to go via the credit card as there will be no excess and your insurance company will probably expect you to try them first anyway.
We had Monarch flights booked just after they went bust and luckily I had the time and the foresight to book replacement flights early that morning. I've posted more about this near to the top of this thread, so won't repeat myself with the detail. I had to get the money back in two bits, the original £300 and the extra £200 but it was a bit like pulling teeth, but if you understand your rights, and get advice from MSE, you will be refunded.
My advice to you and anyone else facing loss of flight only bookings paid for by credit card is to look for new flights straight away if any announcement is made that TC go bust, because they'll get very expensive, very quickly for up to and including October half term and then sell out.
I also expect that, if they do go bust in the short term, it will be about 4 am tomorrow morning because that's what happened with Monarch because they have to cancel the air operators licence and they have to do it when there are no flights in the air.
So I'd be prepared to look for which flights you could book today and then get up at 5/6 am tomorrow morning, see the news and if they've gone, get booking flights straight away. If you wait until even 8/9 am it could be too late.