I would go. Wrentham is a pretty good outlet anyway. They've got a great Saks, Barneys, and BCBG store and other designer stuff. They have a Salvatore Ferragamo store. So, even if the Bloomies isn't that good, I'm sure you won't regret it.
I went to the outlets a few days ago, and didn't even realize there was a Bloomingdale's outlet. When I got the AAA booklet, it had a separate coupon for that outlet, so I decided to check it out. I was looking for a handbag, and they had lots of MBMJ, Linea Pelle (so fun to finally in person!!), RM, Juicy, and maybe a couple of others that I can't remember. I also found a MK leather jacket that I was hoping would work, but it didn't fit. I did look at some of the clothing, but nothing really grabbed me. Prices were pretty good, but a lot of it seemed like stuff I can find at Macy's or even TJMaxx.
Bloomningdales has an outlet at Wrentham now? Wow. I always make this a stop when I go back home to MA. Wrentham is a really good outlet mall and definitely worth the trip. I miss shopping there often.
Make sure you join the premium outlets.com VIP club online too...there are often additional coupons for the outlets to print out in addition to the coupon book...and if you are not an AAA member there is a voucher to print to get the coupon book at the customer service desk. There is usually a $20 off $100 purchase coupon for the Bloomies outlet. Just know that it is not in the main outlet section- it is near Restoration Hardware/Unos at the main entrance. So hit it up on your way into the other shops or on your way out- it is too far away to park and walk. =)