Like Whittierider, I'm unfamiliar with this particular bike.
As has often been said here, you can tour on any bike. Hybrid/comfort bikes such as this one are often criticised on this site on the grounds that they do nothing really well - but the converse of this is that they do many things moderately well. You've already found that the bike handles trails satisfactorily. It will certainly get you up almost any hill with that bail-out gear.
The answer to your question depends in part on how far you'll be riding each day - I don't know the event you're planning to participate in. If you're managing 40 miles a day now, and think you could cope with another 10 or 15 per day, then it seems that you and the bike will cope if that's what the event involves. If there are some 100-mile days, and the event is for serious riders, then the bike's limitations will become more serious.
I started (well, re-started) my interest in cycling with a bike not unlike yours. It took me on some long multi-day supported rides, with days of between 50 and 70 miles, and I enjoyed them. (By a supported ride, I mean one in which the organisers carry your luggage for you, and you don't have to carry your own food and cooking equipment.) At the end of 18 months, I had a clear idea of the kind of bike I wanted to upgrade to. One problem I did encounter was soreness in the wrists from constantly keeping my hands horizontal. You may not experience this - it seems that you're already spending longish days on the bike.
To sum up: This is not the ideal machine, but you're at the start of your biking career and you should plan to enjoy the experience - not try to be first into camp each day. You won't be.
To see a good dedicated touring bike, look at the Trek 520 or the Surly Long Haul Trucker.