@jo1944 ,
I am not sure I understand the question. Obviously, you can on your US tax return recognize the full or any portion of the earned interest. This is true as long as the total amount is recognized somewhere between your and your spouse's return. Therefore , what are you trying to achieve. As far as I know there is no language in the tax treaties requiring a specific apportionment of earnings between spouses ( except of places like Mexico where communal rules are followed i.e. all marital earnings are equally shared/owned by the spouses ).
Does this answer your query ?
BWT -- as a US person , even with a foreign tax-Home, you are still subject to FBAR ( form 114 ate FinCen ) and FATCA ( form 8938 along with your return) regulations.
Is there more I can do for you ?