no, they won't add up. In Postpay, since past one year, as a promotion !dea is providing 100MB 3G data valid for 3 days that too on regular basis like twice or thrice in a month but on 3G network 100 MB goes like pheww....
With 4G, it seems that for prepay customers, there is a raise both in terms of data as well as validity just to entice customers so that they can help churn out 4G paid data packs by hooking end consumers against high speed data connectivity.