IHG has no special linked spousal accounts. Anyone can xfer points to another IHGer at usd5/1k but as you can buy points (points+cash award nights option) for only usd7/1k that is of minimal benefit.

Hilton have some older 'linked 'accounts set up under old rules with points having a free xfer between spouses, but or some year now new accounts have to pay to xfer points, just like with IHG.

Can only suggest you both signup for IHG Rewards membership, then each account can participate in the various bonus point codes posted on FT. If you are both new to IHG with new accounts, and thus never having used the numeric bonus codes, you could well earn a large bonus on first stay as bonus codes are stackable so get triggered by he same stay.

Earn+Burn points for free room nights still seems to be easiest to get free nights for least stays with IHG for me over Hilton.