Definitely, I have a feeling trying to romance both of them will cause a rift in that friendship for sure. Jill trusts Bella a lot and Bella well she wants something and unfortunately its the man she passed to Jill.
It may not be as much of an issue if we choose to pursue one or the other though; unless it's just forced to happen. Everything's nice now because both of them are mature about it (and Jill is unaware of what MC does with Bella atm if take that route). When things start getting official with either of these ladies it's probably going to start getting ugly. Neither strike me as the type that like to have their affections toyed with.