Bonnie has done her research and knows exactly where James and Alyssa are. After she sends both of them bullets with their names engraved into them, she begins her journey to find the pair, so she can murder them. She finally is united with James and Alyssa in episode four and desperately tries to get each of them alone so she can shoot them.
It wouldn't be The End of the F***ing World without plans going awry, so it's fitting that it takes Bonnie multiple attempts to corner James and Alyssa. It isn't until the seventh episode that we finally see Bonnie alone with the pair, ready to make her move on them.