You might try stores that selling tank tops for running -- some of them have pockets, although they are probably smaller than the ones on bike jerseys.
I know Lucy has sports bras with removeable cookies, but I'm pretty sure they don't carry cycling tank tops.
- Gray 2010 carbon WSD road bike, Rivet Independence saddle
- Red hardtail 26" aluminum mountain bike, Bontrager Evoke WSD saddle
- Royal blue 2018 aluminum gravel bike, Rivet Pearl saddle
Gone but not forgotten:
- Silver 2003 aluminum road bike
- Two awesome worn out Juliana saddles