many people say no but if you give them the correct bond in life then they should be fine. the only things, they have different nutritional needs so you will need to buy 2 types of food, one for the guinea pig and one for the rabbit, unless you but Wagg guinea pig and rabbit food.
the first things is, yuo will need 2 hutches/cages 2 start with perhaps if yuo have their hutch too, one for the rabbit one for the guinea pig then, follow this so they get to know eachother.
day 1- let them smell eachother, keeping one in the cage and let the other smell through the cage bars
day 2- let them on the floor together, perhaps your living room.
day 3- let them in te same cage to play for a while
day 4- leave them in the same cage for a few hours
day 5- do the same as day 4
day 6- try and leave them together all day
day 7- do the same as day 6
day 8- try and leave them together all day and night
do day 8 until they get on with each other, your best bet is though is to have 2 cages, and keep them away maybe, try that though, keep trying but you can't make them get on. if they fight, but becuse they are females are a bit less likely, split them up straight away!
i hope i helped, good luck