Welcome, Wayne!
it is a good idea to post bonuses and bonus changes, even banners for special promos. You likely won’t get any answers a lot of the time when you do this, but people do read it and newbies will be encouraged to sign up with you.
I always encourage managers to post the salient points of their newsletters – it gets read here and oftentimes not in the mail.
Think of your forum like a billboard in a busy intersection. Keep it fresh and it will work for you.