It could work but
Yes it could work, but here is the issue you would face. The VHF unit works in the 2m bandwidth, while Fm radio is a little lower, 1.7m I believe. So the recption is likely to be moderate at best. Another problem is that your Fm radio uses one type of jack and VHF another, You would have to find a coupler that you could attach to make them mate up. Also if you were able to hook them all in , and you had to use your VHF , the power output from your VHF radio would more than likely blow out the reciever in your Fm radio. It's an awful lot of hassle to have just one antenna. Myself I just placed the Fm antenna under the v-berth bunk. Works just fine, great reception. If you decide to go that route, for a coupler, try radio shack, or a electronics store that deals in HAM Radio equipment. Best of luck to ya.