Having and actual road or touring bike for those sorts of rides is just fine. Putting it in car terms...
Hybrid = minivan
Road bike = sport coupe
What gets silly is the idea of having a reeaaalllyyy expensive road bike and expecting it to make the difference. That being said, I prefer to buy expensive art that I can ride rather than hang on the wall.
Don't give up on the group road rides. Ask for advise from the group, but a couple of thoughts to keep in mind... eat/drink enough before/during/after the ride. Get comfortable in a crowd of riders and take advantage of drafting. Keep riding! soon 45 miles will just be a warmup.