The real deal is the FCC has inspected a number of radio stations using FM30b's and passed them all. A few had high gain (3.5db gain) and they still passed and covered way passed the so called 200ft limit. Micro neighborhood broadcasters with 25 milliwatts, are not on the FCC's high priority list; as long as you keep programming clean and don't use call letters to ID your station you will be fine. Slogans are okay; just not call letters.
I know my own personal FM30b does amazing well with the stock antenna; I powered it down so just a square and half were filled up and it still covered a few blocks with a portable radio. I cover very large apartment complexes with the FM30b's I use for my network.
Ramsey has a chart to give you an ideal how far you can cover under part 15 rules; remember FM radios are a lot more sensitive these days than they use to be. I have the chart posted here too: www.radiobrandy.com/part15fm.html
you can click on the chart to super size it.
One user of the FM100b, gets 3 miles from a Ultimate Dipole. It's not a city grade signal, but very listenable on most car radios.
Covering your neighborhood or a few blocks, is not going to get you busted.