If you signed any so called "intellectual property" contract with your employer, go visit a lawyer, show him or her the contract and be prepared to pay for the legal advice.
If not, it very much depends on the jurisdiction.
In a number countries that I know and operate in, if the only legal interaction between the employer and employee is of generic employment nature, anything that you create on your own time, with your own equipment and without using any proprietory technical knowledge that belongs to your employer, you own and are free to do with as you please.
What Wine project might or might not require is up to them. (However, it is my observation that most US entities (such as Wine) blindly assume that there is only one jurisdiction in the world - US, and act accordingly :).
NikNot