I deleted this from a different thread and set up a new one, in the hope of catching someone's eye. I hope that's not against posting rules.

I'm currently the main cardholder of the standard BA Amex card, and my husband is a supplementary card holder. I've been thinking of upgrading to the BA Premier Plus Amex, but because I'm already a BA cardholder I don't get a welcome bonus. So, if I refer my husband for the Premier Plus card, and he makes me a supplementary cardholder, it looks like I'd get 9k avios for referring him and he'd get 26k avios if he spends £3k in 3 months.

I've got a couple of questions that can hopefully be answered by more experienced flyertalkers:

By the time he gets his first 2-4-1 voucher on the his premier plus card, it's likely that I'll have be gold EC and he'll be silver. Is there any disadvantage to being silver vs gold when it comes to finding and booking reward companion flights?

and

I've already booked our 2-4-1 reward flights, travelling in August. Do I need to hang onto my current standard amex card until we travel? I was thinking of cancelling it in order to become eligible for referral to Premier Plus in the future.

Thanks for your help.