I'm not a fan of taping. Just my personal feeling. There is no way to prove that taping works, or doesn't work and it can actually damage the ears and keep them from standing. To me, time and patience is all that is needed.
Give your pup plenty of things to chew on to strengthen the muscles. Relax, the pup is still very young. Forget those people who say the ears should be up by now. That isn't true. Every dog is different, and every pup has their own schedule for when the ears stand. Some are up by 6 or 8 weeks and stay there. Others take nearly a year. There is no rule.
If the ears have ever been up before, they are highly likely to come up again. Just give them time. And stop worrying.