I have to start off with saying that your question is a question of Law and you must know that I am not an attorney and my answer is in no way to be construed as legal advice. You should consult an attorney.
This is a gray area for sure. If you made at a cost to you these fliers and delivered them to your agent (assuming to go into the flier box or be at an opening) then you are only allowed to absorb the cost of half the fliers IF the information is split equally. Meaning half the flier is about the home and half about financing.
HOWEVER if it is all about the house…then you are only allowed to pay for the portion as a percentage of the flier that your “advertisement” takes up.
HOWEVER If this is a FINANCE ONLY FLIER meaning there maybe a picture of the house and your realtor is co-branded- but the purpose and intention of the flier is to showcase the financing you can provide and your services then you SHOULD be fine. To be safer make sure the realtor has a seperate flier for their services, usually it won’t be co-branded.
Also remember that RESPA violations look at the spirit of the law. If you are intentinally offsetting cost for a realtor or giving them ANYTHING of value, then you are in violation.
But you can add their info (co-branding) to your marketing as long as you incur no additional cost and there is no definable value.