You cannot get the Boundless with the Bold, you would need to cancel. You can qualify for an AMEX card however if your Bold is over 24 months old.

You may want to wait as I suspect the AMEX Bonvoy Bevy will be released in about a week or so, which may work better or have a better sign up offer.

If you specifically want the Bold, you need to cancel and then wait 30 days before applying for Boundless