Restaurant Santa Croce and San Polo area?
 

Does anyone have any restaurant suggestions where these two districts meet or within that area?

We loved the pizzas at Antica Birraria La Corte and had them several times, the pannecote was great too.

Although the restaurant is modern inside, it is not ugly and the service is very good. They also have a bar area for drinks.

It is in Campo San Polo, just a quick walk from Rialto Bridge.
At night it is filled with locals.

http://www.restaurantsomh.com/v28.htm

The Slow Travel website is filled with restaurant recommendations for Venice identified by sestri. Like all restaurant recommendations, you may not share the taste buds of those doing the eating and reviewing, but they can be good for identifying places where you'll get friendly service and what to expect in terms of cost.

The choice place in S. Polo is Do Spade, an old and venerable osteria serving very interesting and tasty dishes (donkey stew, for example). Address is Sotoportego de le do spade (named after the osteria, not the other way round!). Don't come too late in the evening, as this is the Rialto market area where everything would close even earlier than elsewhere in Venice (i.e. don't arrive after 8.30 p.m.). Quite good but overpriced fish dishes are to be found nearby at Sora al Ponte.
S. Croce has Capitan Uncino on Campo S. Giacomo dall'Orio as the very best choice. Though the service is by no means good, it's absolutely worth eating there, the kitchen is good, and it's a great place to sit outside on summer evenings, the Campo being the center of one of the most unspoiled neighbourhoods in Venice - genuine town life, no hints of mass tourism there. And above all, the best desserts and the best sgroppino of Venice.
More than this, there are two students' pizzerias (the university is nearby) which are quite good: Ae Oche (not far from Capitan Uncino), and Al Nono Risorto near S. Maria Mater Domini. Plus Venice's one and only vegetarian restaurant, serving quite delicious food: Alla Zucca, just around the corner from Capitan Uncino.
Buon appetito!

There are heaps of good restuarants in the area. I suggest looking at the Slow Trav site for some reccomendations as well as getting hold of a copy of Chow Venice. Alla Zucca is no longer purely vegetarian - it has some meat - but still has an amazing range of vegetables both as meals and side dishes. You'll need to book ahead and they often run 2 sittings.

You are correct, and it was actually never exclusively vegetarian - but it's unusual enough that an Italian restaurant has mostly vegetarian dishes, and so, for Italians at least, it qualifies as a vegetarian restaurant (actually, my Venetian friend refuses to go there because he despises Vegetarian kitchen, and he doesn't care whether they're serving meat, too - he simply doesn't go to a "vegetarian" place).