Since its not an investment account, anti-tying rules do not apply. The only regulation to be aware of is Reg E 1005.10(e) which prohiibts you requiring automatic payments to the loan.
That being said, how much market research have you done? Every bank I've worked for as an employee or with as a consultant ended up with a bunch of expensive deposit accounts with $1.00 sitting in them doing nothing but eating into the bottom line.
Also, since this is a condition of extending credit, youshould also evaluate any potential disparate impact risks for fair lending.
_________________________
Sola Gratia, Sola Fides, Sola Scriptura, Solus Christus, Soli Deo Gloria!
www.tcaregs.com