Yep, you're not the first to report those April bonus points not being awarded, you're not alone.
We've been told by a Community manager, that it can take around a month for them to appear on your account, so hopefully they'll appear in the next few days.
Otherwise, you can try and contact Nectar's helpline see what they say, but they may just send you to eBay, who'll recommend contacting Nectar.
Please, if you do get through with any answer come back to us and tell us , so we can help others, thank you.
@t1962p