We're sure that your child is receiving some phonics instruction in the second grade reading class. However, teachers using the whole-word approach do not teach structured phonics in the usual sequential order and they will not devote as much time to working on phonics as teachers who use the phonics approach.
Since you feel that your child was making better progress with the phonics approach, talk with the teacher and ask how you can supplement your second grader's classroom work with more time at home on phonics. You need to collaborate with the teacher. Otherwise, your child may be confused if the teacher is working on certain sounds and you are teaching others.
Don't limit your efforts in improving your child's reading to phonics exercises and playing phonics games. Make it a point to read to your child each and every day. Not only will it stimulate your child's interest in reading; it will also serve as a model for your child to imitate.