In addition to JT’s advice re looking to see if there is a by-law, can you ask the committee to provide evidence of how the costs have been assessed? If the cost is excessive then the imposition of a security bond could be deemed to be a penalty rather than the legitimate recovery of expenses incurred by the strata scheme.
There are other ways that an OC can recover costs if common property is damaged during a renovation that do not involve a hefty security deposit.
Fortunately these types of security bonds are illegal in Qld. The BCCMA states : A by-law (other than an exclusive use by-law) must not impose a monetary liability on the owner or occupier of a lot included in a community titles scheme.