I know that stealing a bike is crime. My question is: can someone who steals a bike get additional charges if they have to break a lock as compared to picking up an unlocked bike?
We are talking about larceny and larceny & destruction of property in the two cases. So at the minimum, there are more laws that apply. But what are the laws?
Florida names its Larceny statute... Theft:
(1) A person commits theft if he or she knowingly obtains or uses, or endeavors to obtain or to use, the property of another with intent to, either temporarily or permanently:
(a) Deprive the other person of a right to the property or a benefit from the property.
Destroying someone's else property in Florida is in the statute on Criminal Mischief:
806.13 Criminal mischief; penalties; penalty for minor.—
(1)(a) A person commits the offense of criminal mischief if he or she willfully and maliciously injures or damages by any means any real or personal property belonging to another, including, but not limited to, the placement of graffiti thereon or other acts of vandalism thereto.
So, yes, you would additionally get the criminal mischief charge, but... that only grants monetary damages of 250 USD plus the damages done to the items for first timers, but it can become upgraded to a felony in the third degree - which has a maximum limit of 5 years. Note that damaging items in the course of theft is specifically an aggravating factor for the theft charge, if grand theft is combined with property damage of 1000 USD and more.
A bicycle costing between 750 and 5000 USD is grand theft, felony in the third degree according to 812.014.(2)(c)1. This is also the 5 years limit. One could get both sentences... but still only sit 5 years, because often sentences are served concurrently, only rarely consecutively. So, no, you do not necessarily commit a higher offense just for breaking the lock - you'd need to have a 1000 USD damage for that - but you most certainly commit additional offenses that can result in a higher verdict in the end.