You really don't *need* to do two places, esp. if BRU has what you want & guests can go there (it's local etc.) However, two thoughts crossed my mind you may want to consider:
1) Target used to (so check, they may or may not anymore) offer a gift card just for registering. So, maybe create a registry with a few items that are okay if duplicated--say, diapers, wipes, clothing items, bath items that are consumable so you'll always need more, etc.--and then you get the gift card whether anyone buys there or not;
2) Some people, esp. those who don't have a lot of time, but like to shop at Target anyway, may appreciate having an option that won't require a second trip for them to hit your registry.
Basically, if you register for stuff that is pretty basic (as listed in #1) you shouldn't even have a problem with returns, since you'll always need diapers and such. Good luck!