Do the rebate shares have the same start date as the initial purchase or does the 5-year clock start on the new date these were reinvested?

Rebate shares are treated as a new VCT investment for tax purposes. This means the five-year holding period starts from the date the rebate shares are allotted, rather than the date of the original investment. If the shares are sold within five years, any Income Tax relief claimed on those shares may need to be repaid.